refactor(config): remove stencil extras

[liamdebeasi]

Docs PR: ionic-team/ionic-docs#2676

Pull request checklist

Please check if your PR fulfills the following requirements:

• Tests for the changes have been added (for bug fixes / features)
• Docs have been reviewed and added / updated if needed (for bug fixes / features)
  • Some docs updates need to be made in the ionic-docs repo, in a separate PR. See the contributing guide for details.
• Build (npm run build) was run locally and any changes were pushed
• Lint (npm run lint) has passed locally and any fixes were made for failures

Pull request type

Please check the type of change your PR introduces:

• Bugfix
• Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation content changes
• Other (please describe):

What is the current behavior?

The Stencil team would like to deprecate the extras option in Stencil v3.

What is the new behavior?

• Bumped the minimum Firefox version for v7 from Firefox v63 to v70. I chose v70 because it gives us ~3 years of Firefox browser support.

• These extras options have been removed:

1. dynamicImportShim: Only needed on <= Edge 18 and <= Firefox 67 according to https://stenciljs.com/docs/config-extras#dynamicimportshim
2. initializeNextTick: This is needed to work around an old Angular issue, though that issue is possibly no longer a problem. We should observe any negative side effects during the v7 beta.
3. scriptDataOpts: This lets you call defineCustomElements from a vanilla JS app and a) load Ionic from a CDN and b) provide a config. This is not used anymore and our docs recommend adding the script tags yourself: https://ionicframework.com/docs/intro/cdn

Does this introduce a breaking change?

• Yes
• No

Other information

Note: Removing initializeNextTick caused a visual diff in Safari with iOS mode/RTL direction that I was unable to identify the root cause for. Some of the text in item/test/fill appears to be clipped by 1-2px. I am unable to reproduce this locally, so I decided it would be best to process despite this diff:

I have updated the screenshot test with the new diff that way we a) still get test covered for iOS mode/RTL direction on Safari and b) catch any diffs if this changes again.

Ryan believes this may be connectedCallback-related with a possible timing issue:

extras.initializeNextTick feeds into a BUILD conditional of the same name, BUILD.initializeNextTick. When the latter is truthy, connectedCallback wraps component initialization (a Stencil process) in a promise. Possible timing issue: https://github.com/ionic-team/stencil/blob/e1d17fbc51bfe592b5419b314befe1559088da73/src/runtime/connected-callback.ts#L91-L99

[liamdebeasi]

Blocked on #26454