fix(ios): scroll assist sizes input correctly (#27253)

Issue number: resolves #27249

---------

<!-- Please refer to our contributing documentation for any questions on
submitting a pull request, or let us know here if you need any help:
https://ionicframework.com/docs/building/contributing -->

<!-- Some docs updates need to be made in the `ionic-docs` repo, in a
separate PR. See
https://github.com/ionic-team/ionic-framework/blob/main/.github/CONTRIBUTING.md#modifying-documentation
for details. -->

<!-- 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 cloned input/textarea for scroll assist is not sized correctly. For
legacy inputs, this causes the clone to be off by ~1px because it does
not have the correct height. For modern inputs, this causes the same bug
as the legacy inputs plus cloned inputs overlap any floating/stacked
labels. This was not a concern for legacy inputs because those inputs
did not contain the label element where modern inputs do.

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

- Sets `bottom: 0` for cloned inputs so they have the correct height
- Sets `position: relative` on the `.native-wrapper` so the cloned input
does not flow outside of the parent container.

**Before**

| Modern Input | Legacy Input |
| - | - |
| <video
src="https://user-images.githubusercontent.com/2721089/233385644-3c15f98e-2646-41e1-b206-34c505791bde.MP4"></video>
| <video
src="https://user-images.githubusercontent.com/2721089/233385681-8d682222-44b4-4cdc-b0de-96ed3fd38792.MP4"></video>
|


(Note: The legacy input bug is subtle -- the input only shifts by ~1px)

**After**

| Modern Input | Legacy Input |
| - | - |
| <video
src="https://user-images.githubusercontent.com/2721089/233385911-243dea95-39b4-4d81-bfe9-26e52382a702.mp4"></video>
| <video
src="https://user-images.githubusercontent.com/2721089/233386237-2c9eede3-ca91-429b-8a35-15428529a883.mp4"></video>
|


## 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. -->

core/src/components/input/input.scss

@@ -177,7 +177,7 @@
 // otherwise the .input-cover will not be rendered at all
 // The input cover is not clickable when the input is disabled
 .cloned-input {
-  @include position(0, null, null, 0);
+  @include position(0, null, 0, 0);
 
   position: absolute;
 
@@ -307,6 +307,8 @@
 .native-wrapper {
   display: flex;
 
+  position: relative;
+
   flex-grow: 1;
 
   width: 100%;

core/src/components/textarea/textarea.scss

@@ -190,7 +190,7 @@
 // otherwise the .input-cover will not be rendered at all
 // The input cover is not clickable when the input is disabled
 .cloned-input {
-  @include position(0, null, null, 0);
+  @include position(0, null, 0, 0);
 
   position: absolute;
 
@@ -269,6 +269,8 @@
 .native-wrapper {
   display: flex;
 
+  position: relative;
+
   flex-grow: 1;
 
   width: 100%;