Check for supported API version annotation when loading extensions

[jordojordo]

Summary

Fixes #11695

Occurred changes and/or fixed issues

• Replaced the environment variable injection for UI_EXTENSIONS_API_VERSION in vue.config.js
• Updated the condition to load an extension based on the extensions api version annotation
  • Now when an extension does not contain the catalog.cattle.io/ui-extensions-version annotation it will now be considered a legacy extension, and will not be loaded
  • This annotation will now be required for Vue3 extensions and will need to have a version >= 3.0.0
• Added a small method to coerce the UI_EXTENSIONS_API_VERSION to remove any pre-release modifiers

Areas or cases that should be tested

• Load an extension with the required API version >= 3.0.0
• Load an extension with the required API version >= 2.0.0
• Load an extension without the catalog.cattle.io/ui-extensions-version annotation

Areas which could experience regressions

Screenshot/Video

Checklist

• The PR is linked to an issue and the linked issue has a Milestone, or no issue is needed
• The PR has a Milestone
• The PR template has been filled out
• The PR has been self reviewed
• The PR has a reviewer assigned
• The PR has automated tests or clear instructions for manual tests and the linked issue has appropriate QA labels, or tests are not needed
• The PR has reviewed with UX and tested in light and dark mode, or there are no UX changes

[aalves08]

Would recommend closing this in favor of #12071