Migrate border and margin classes to Tailwind

[silverwind]

Used all existing css vars, other migrations are 1:1.

[silverwind]

Also includes migration of gt-border-secondary-* now.

[wxiaoguang]

Fix more problems in code:

• 500.tmpl: use divider instead of bottom border
• DiffCommitSelector.vue: use well-defined CSS classes, remove all CSS helpers
• repo-diff-commit.js: separate the CSS class names for add method
• repo/settings/options.tmpl
  • The old "bottom border" is not right, so it could be just removed.
  • The old code {{if}}{{end}} block doesn't match the HTML, so fix the {{end}} lines

[silverwind]

repo-diff-commit.js: separate the CSS class names for add method

Good catch, this would have raised a DOMException: DOMTokenList.add: The token can not contain whitespace. error.

[wxiaoguang]

And one more fix for DashboardRepoList.vue:

• remove the "top border", use "divider" instead.

[silverwind]

remove the "top border", use "divider" instead.

Divider will introduce margin, is it not an issue?

[wxiaoguang]

remove the "top border", use "divider" instead.

Divider will introduce margin, is it not an issue?

I added "gt-my-0" when it is necessary 😁

[silverwind]

lgtm