Formatting Dart code + enforcing it on CI.

[isoos]

Note: I have no idea whether this is good/required for the template files with lots of changes, but for the rest of the files it seems somewhat important to make them consistent with other project workflows where the dart format is prerequisite of the approval.

I've extended the tool to run dart format . after the tool generates the template files.

I've also extended the CI tool to run it before the dart analyzer is run (in the same command block, for simplicity, and also because there is very little reason to run them separately).