1. use grid instead of table, completely drop "ui table" from that list
2. move some "commit sign" related styles into a new file by the way (no
change) because I need to figure out where `#repo-files-table` is used.
3. move legacy "branch/tag selector" related code into repo-legacy.ts,
now there are 13 `import $` files left.
wxiaoguang
4814f43af7