RN 0.81: Build all library components against react-native 0.81

[JasonVMo]

Platforms Impacted

• all

Description of changes

This converts all the packages in the library to RN 0.81 / React 19 with the exception of the test apps which are still built against RN 0.74. This is a pretty noisy change, mainly due to type changes. Some notes:

• with react 19, you need to wrap render calls for react-test-renderer in act calls to force synchronous mode.
• certain tests had to switch away from win32 as the platform, resulting in some snapshot changes in those packages. This was due to unimplemented APIs on Win32 for the test renderer.
• the filters in adapters have been removed, they were unnecessary and have been for some time.
• I reworked the core IViewProps types to ensure that they can be assigned correctly and merge in a reasonable fashion.
• I pointed most helper types to the ones from the various RN libraries now that types exist across the board.
• accessibilityPositionInSet was wrong, should be accessibilityPosInSet (or maybe the area prop)

Apologies for the giant review. It was hard to split it up beyond what I had done already in previous PRs.

Verification

• test runs, some manual testing, pipelines