BREAKING CHANGE: `ion-picker` and `ion-picker-column` have been renamed to `ion-picker-legacy` and `ion-picker-legacy-column`, respectively. This change was made to accommodate the new inline picker component while allowing developers to continue to use the legacy picker during this migration period.

… ion-picker-column (#28589)

Issue number: #

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issue. -->

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## What is the current behavior?
<!-- Please describe the current behavior that you are modifying. -->

## What is the new behavior?
<!-- Please describe the behavior or changes that are being added by
this PR. -->

-
-
-

## Does this introduce a breaking change?

- [ ] Yes
- [ ] No

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and migration path for existing applications below. -->


## Other information

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screenshots of how the component looks before and after the change. -->

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Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: Liam DeBeasi <liamdebeasi@users.noreply.github.com>
Co-authored-by: Sean Perkins <13732623+sean-perkins@users.noreply.github.com>
Co-authored-by: ionitron <hi@ionicframework.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Sean Perkins <sean@ionic.io>
Co-authored-by: Éric Le Maître <eric.erwan.le.maitre@gmail.com>
Co-authored-by: Shawn Taylor <shawn@ionic.io>

Issue number: Internal

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<!-- Please do not submit updates to dependencies unless it fixes an
issue. -->

<!-- Please try to limit your pull request to one type (bugfix, feature,
etc). Submit multiple pull requests if needed. -->

## What is the current behavior?
<!-- Please describe the current behavior that you are modifying. -->

The new picker component does not have a counterpart for the `prefix`
and `suffix` properties on the old picker column.

## What is the new behavior?
<!-- Please describe the behavior or changes that are being added by
this PR. -->

- `prefix` and `suffix` slots added.
- Picker items wrapped in a new `.picker-opts` element for positioning
purposes, similar to the legacy picker column. This necessitated
additional changes to functionality and styling, since previously the
items were direct descendants of the host.
- New `setFocus` method added. This gets around a browser bug in Firefox
where calling `focus()` on the column doesn't correctly move focus, as
the nearest focusable element (`.picker-opts`) is in the shadow DOM.

## Does this introduce a breaking change?

- [ ] Yes
- [x] No

<!-- If this introduces a breaking change, please describe the impact
and migration path for existing applications below. -->

While you can no longer call `focus()` on the column in Firefox and must
use `setFocus()` instead, this isn't considered a breaking change
because this component isn't public API yet.

## Other information

<!-- Any other information that is important to this PR such as
screenshots of how the component looks before and after the change. -->

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Co-authored-by: ionitron <hi@ionicframework.com>

Issue number: N/a

---------

<!-- Please do not submit updates to dependencies unless it fixes an
issue. -->

<!-- Please try to limit your pull request to one type (bugfix, feature,
etc). Submit multiple pull requests if needed. -->

## What is the current behavior?
<!-- Please describe the current behavior that you are modifying. -->

The team would like to add a way of using the picker inline with page
content.

## What is the new behavior?
<!-- Please describe the behavior or changes that are being added by
this PR. -->

- This PR integrates the column option component with the rest of the
picker so that is functional. This PR is a combination of commits from
previously reviewed PRs.

## Does this introduce a breaking change?

- [ ] Yes
- [x] No

<!-- If this introduces a breaking change, please describe the impact
and migration path for existing applications below. -->


## Other information

<!-- Any other information that is important to this PR such as
screenshots of how the component looks before and after the change. -->

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Co-authored-by: ionitron <hi@ionicframework.com>

Issue number: N/A

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## What is the current behavior?
Picker has the following CSS variables for styling:
`--wheel-fade-background-rgb` and `--wheel-highlight-background`

These variables make sense when used from `ion-datetime`, but picker
does not need the `wheel` prefix.

## What is the new behavior?

### Datetime

- Adds `--wheel-highlight-border-radius` 
- Keeps `--wheel-fade-background-rgb` and `--wheel-highlight-background`
- Assigns these variables to picker's new variables

```scss
ion-picker {
  --highlight-background: var(--wheel-highlight-background);
  --highlight-border-radius: var(--wheel-highlight-border-radius);
  --fade-background-rgb: var(--wheel-fade-background-rgb);
}
```

### Picker 

Renames `--wheel-fade-background-rgb` and `--wheel-highlight-background`
and adds another CSS variables to `ion-picker`:

- Renames `--wheel-fade-background-rgb` to `--fade-background-rgb` 
- Renames `--wheel-highlight-background` to `--highlight-background`
- Adds `--highlight-border-radius`

## Does this introduce a breaking change?

- [ ] Yes
- [x] No

## Other information

PR to update the [Datetime docs](ionic-team/ionic-docs#3303)

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Co-authored-by: ionitron <hi@ionicframework.com>