60116 [flutter_tools] Add support for web in plugin template. (cla: yes, tool, waiting for tree to go green)

60119 [flutter_tools] separate target platform, host platform, and architecture (cla: yes, tool)

60127 [versions] update all versions and fix tool tests (cla: yes, team, tool)

60144 [flutter_tools] more test fixes (cla: yes, tool)

60147 Revert “[flutter_tools] separate target platform, host platform, and architecture” (cla: yes, tool)

60156 [flutter_tools] even more test fixes (cla: yes, tool)

60159 Make flutter create . on plugins also regenerates files for platforms already supported (cla: yes, tool, waiting for tree to go green)

60163 Consider the Linux template stable (cla: yes, tool)