[pointer_interceptor] Update min Flutter version (flutter#683)

[web_benchmarks] Fix _RecordingWidgetsBinding to conform to latest API (

flutter#700)

[pigeon] a few tweaks to the output after having upgraded video_player (

flutter#663)

[pointer_interceptor] Mark `PointerInterceptor` as invisible (flutter…

…#529)

[xdg_directories] Mark as Linux-only (flutter#643)

[pointer_interceptor] Allow conditional pointer interception (flutter…

…#538)

[pigeon] Added non-null fields (flutter#549)

* [pigeon] Added non-null types for fields

[all] Update repo links to 'main' (flutter#552)

Replaces 'tree/master/...' with 'tree/main/...' in pubspec `repository`
and podspec `source` links, now that `main` is the default branch.

No version change: `master` is being mirrored for the foreseeable
future, so there's no urgency on this; updates can go out as plugins
are updated naturally.

No CHANGELOG change: This is a mechanical mass change.

[all] Update repo links to 'main' (flutter#552)

Replaces 'tree/master/...' with 'tree/main/...' in pubspec `repository`
and podspec `source` links, now that `main` is the default branch.

No version change: `master` is being mirrored for the foreseeable
future, so there's no urgency on this; updates can go out as plugins
are updated naturally.

No CHANGELOG change: This is a mechanical mass change.

[pigeon] Fix too little information when having an exception (flutter…

…#545)