Fix and restyle menu on code line (#15913)

* Fix and restyle menu on code line

* fix multiline and more tweaks

* move to separate files

* remove has-context-menu class

Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: techknowlogick <techknowlogick@gitea.io>

web_src/less/themes/theme-arc-green.less

@@ -153,12 +153,6 @@
   background: #353945;
 }
 
-.ui.link.list .item,
-.ui.link.list a.item,
-.ui.link.list .item a:not(.ui) {
-  color: #dbdbdb;
-}
-
 .ui.red.label,
 .ui.red.labels .label {
   background-color: #7d3434 !important;