Use secondary pointing menu for tabs on user/organization home page (#24162)

Close #24108

Use secondary pointing menu for tabs on user/organization home page so
the tabs look the same.
Main changes:
1. modified a part of dom structure in
`templates/user/overview/header.tmpl` to make it the same as
`templates/org/header.tmpl` in order to produce the same ui.
2. Move some css to `web_src/css/shared/repoorgshared.css` to make them
shareable between `templates/user/overview/header.tmpl` and
`templates/org/header.tmpl`

After:


https://user-images.githubusercontent.com/17645053/232400617-2add5bec-d483-4ab1-b48d-eaee157f7b09.mov

For further improvements. Need some thoughts: 

For [this
TODO](729ad294cb/templates/user/overview/header.tmpl (L1)),
it is viable to make it a shared template for [this
part](729ad294cb/templates/user/overview/header.tmpl (L2-L17))
and [this
part](729ad294cb/templates/org/header.tmpl (L1-L16))
because they are the same except for the variable. But for the menu
parts, they are quite different so might not be suitable to use a shared
template. So need some thoughts and advice about extracting the shared
template from these two headers.

---------

Co-authored-by: Giteabot <teabot@gitea.io>

web_src/css/index.css

@@ -2,6 +2,7 @@
 
 @import "./animations.css";
 @import "./shared/issuelist.css";
+@import "./shared/repoorg.css";
 @import "./features/dropzone.css";
 @import "./features/gitgraph.css";
 @import "./features/heatmap.css";