Updates Windows and Linux templates to use the new PluginRegistrarManager, improving lifetime handling and reducing boilerplate.

49891e065 Roll src/third_party/skia 04513752fd6e..3ef77ddf9ec4 (3 commits) (flutter/engine#17530) (#54156)

* 094563566 Roll src/third_party/skia cc8a76f3c763..04513752fd6e (22 commits) (flutter/engine#17529)

* faf44fed5 Improve C++ plugin lifetime handling (flutter/engine#17489)

* 4b69cf2c4 [tools][fuchsia] Do not tar debug symbol CIPD uploads (flutter/engine#17506)

* 19a7fbf02 Fixed nullability in plugin header and overridden type mismatch error. (flutter/engine#17532)

* ab434c554 Revert "[tools][fuchsia] Do not tar debug symbol CIPD uploads (#17506)" (flutter/engine#17537)

* fd2f0d290 Roll fuchsia/sdk/core/linux-amd64 from Ezm2f... to 3yOjK... (flutter/engine#17525)

* 03bbd7c81 Roll src/third_party/dart 05103dfe5a0e..a8251f820b09 (4 commits) (flutter/engine#17526)

* dabda2c66 Roll fuchsia/sdk/core/mac-amd64 from LDdBU... to wZ5qZ... (flutter/engine#17527)

* df257e59c Roll src/third_party/dart a8251f820b09..1210d27678a0 (5 commits) (flutter/engine#17528)

* Updated bin/internal/fuchsia-linux.version

* Updated bin/internal/fuchsia-mac.version

* Increase memory limit for analyze-linux

This moves the app template more toward being a more generic starting
point for any Flutter application, eliminating some hard-code
assumptions about there being a single window/engine pair that is
directly bound to the life of the application:
- Moves the runloop into its own class, making it capable of servicing
  any number of engine instances.
- Moves the logic for setting up a window containing only a Flutter view
  into a window subclass for ease of re-use.
- Makes quit-on-window-close an optional property. (Long term this
  should be even more generic, like a quit-when-last-window-closes
  option, but this is a short-term improvement that removes the binding
  between the runloop and the window).
- Allows for multiple instances of Win32Window to exist without issues
  relating to the window class registration.

Since there are getting to be a non-trivial number of files associated
with the runner, this moves the source into a runner/ directory, as is
already done on some other platforms.

Note that creating multiple Flutter windows at the same time still
doesn't work correctly even with this change, but this addresses some of
the known issues, and makes it easier to test in the future (e.g., for
debugging engine-level issues with multiple instances).

Fixes #45397

This reverts commit d6b09626.

9b8dcc7ec Roll src/third_party/dart 987ad1d96748..05103dfe5a0e (2 commits) (flutter/engine#17522) (#54064)

f1f7d5db5 Roll src/third_party/dart a7f1a5e677e5..987ad1d96748 (1 commits) (flutter/engine#17520) (#54056)

https://github.com/flutter/flutter/issues/54017

* e55b4476f Use const refs in for loops where reasonable (flutter/engine#17484)

* e2b86556b Roll src/third_party/skia 8efbbbc0d1d4..e70e0c055f56 (1 commits) (flutter/engine#17496)

* a9c6222cd Roll fuchsia/sdk/core/mac-amd64 from 6V5BR... to tKvUB... (flutter/engine#17497)

* fa0907512 Roll fuchsia/sdk/core/linux-amd64 from -jFTb... to TWx2R... (flutter/engine#17498)

* 983d1e170 Fix include paths of fml/time headers in the shell and rasterizer (flutter/engine#17502)

* 09bc1fc45 Small updates to objcdocs (flutter/engine#17151)

* Remove network images from cache on any exception during loading