This reverts commit 5fd259be.

= gets escaped into %3D which seems to be tripping up cmake on windows since % is a control character. Switch to base64 encoding, since this does not have % nor , in the output character set.

This change is not trivially cherry pickable, and isn't tested on windows aside from my local, manual tests due to the planned CI work not being complete yet.

Fixes #75017
Fixes #74705

* opt out the flutter tool

* oops EOF

* fix import

* Update tool_backend.dart

* Update daemon_client.dart

* fix more

There have been some more additional reports of a missing 'package:characters' import after upgrading flutter. This has me concerned that our pub caching logic is incorrect. Instead of the tool attempting to guess when pub should be run, always delegate to pub.

Also takes an opportunity to fix the kernel snapshot depending on the .packages or package_config. Due to the generated: date field this causes extra rebuilds. Instead when pub get is run, write out an additional file with just the package contents and version.

Fixes #66777
Fixes #65723

HACKTOBERFEST

[flutter_tools] support code size tooling on iOS, linux, windows, macOS, and Android on Windows (#63610)

Adds support for size analysis on iOS, macOS, linux, and Windows - using an uncompressed directory based approach. The output format is not currently specified.

Adds support for size analysis on android on windows, switching to package:archive

Updates the console format to display as a tree, allowing longer paths. Increases the number of dart libraries shown (to avoid only ever printing the flutter/dart:ui libraries, which dominate the size)