[flutter_tools] generate empty plugin registrants for winuwp and fix local engine for winuwp_ (#79827)

Adds the rest of the scaffolding for building a UWP application. The actual build functionality needs to be implemented, but could use buildWindows as an example (if it is going through cmake)

#14967

* opt out the flutter tool

* oops EOF

* fix import

* Update tool_backend.dart

* Update daemon_client.dart

* fix more

This reverts commit 28db5a0f.

This reverts commit a9a35d10.

This reverts commit aab9a76e.

This reverts commit abdd65fc.

This reverts commit b7708831.

The tool observes a large number of unhandled exceptions during the file copy portion of flutter create. it is difficult to tell whether the permission issue is caused by the source/destination, or whether it is due to a bug in dart:io.

To work around this, implement a permission check for both the source and dest files. If either fails, the tool can exit with a more specific message.

If these checks pass, then perform the actual copy. If the copy fails, fallback to manually copying the bytes

This reverts commit dd9323bd.

HACKTOBERFEST

Generates version.json in web directory of project. version.json can be used in the future version of package_info which will support web. version.json has the following keys : app_name, version and build_number. This file is generated every time a user runs or builds the project.
Co-authored-by: Jonah Williams <jonahwilliams@google.com>