Modify width of ui container, fine tune css for settings pages and org header (#24315)

Close #24302 
Part of #24229, Follows #24246
This PR focused on CSS style fine-tune, main changes:

1. Give `.ui.ui.ui.container` a width of `1280px` with a max-width of
`calc(100vw - 64px)`, so the main contents looks better on large
devices.

2. Share styles for table elements in all levels settings pages to fix
overflow of runners table on mobile and for consistency (The headers on
mobile can be further improved, but haven't found a proper way yet).

3. Use [stackable
grid](https://fomantic-ui.com/collections/grid.html#stackable) and
[device column width](https://fomantic-ui.com/examples/responsive.html)
for responsiveness for some pages (repo/org collaborators settings
pages, org teams related page)

4. Fixed #24302 by sharing label related CSS in reporg.css

5. Fine tune repo tags settings page

---------

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

templates/repo/issue/labels/label_list.tmpl

@@ -30,11 +30,11 @@
 		{{range .Labels}}
 			<li class="item">
 			<div class="ui grid middle aligned">
-				<div class="nine wide column">
+				<div class="eight wide column">
 					{{RenderLabel $.Context .}}
 					{{if .Description}}<br><small class="desc">{{.Description | RenderEmoji $.Context}}</small>{{end}}
 				</div>
-				<div class="four wide column">
+				<div class="five wide column">
 					{{if $.PageIsOrgSettingsLabels}}
 						<a class="ui left open-issues" href="{{AppSubUrl}}/issues?labels={{.ID}}">{{svg "octicon-issue-opened"}} {{$.locale.Tr "repo.issues.label_open_issues" .NumOpenIssues}}</a>
 					{{else}}