Limit max-height of CodeMirror editors for issue comment and wiki (#18271)

* Make the wiki editor bar sticky for longer wiki edits

On codeberg community it was requested to make the wiki editor toolbar sticky for longer wiki posts, so one wouldn't have to scroll to the top to use it. (Reference; https://codeberg.org/Codeberg/Community/issues/533).

In order to make this happen, the .editor-toolbar class needs to become position: sticky, and we need to fix it's transparent background and border-bottom. Because the bottom disappears, we add it. This makes the border become a double border, because the CodeMirror area defines borders for all. As such I've added a border-top: none, on the wiki write tab for the CodeMirror class.

* Make the issue bar in the issue view sticky for issue #10675

In issue #10675 it's requested to make the issue bar sticky upon scrolling in the issue view. The proposed change changes inline html, which is not desirable. As such I've added the position sticky option to it's container, and fix the background upon scrolling.

* Make linter happy on _repository.less

Fix 0px -> 0 to make the linter happy.

* Make linter happy on _editor.less

Fix 0px -> 0 to make the linter happy.

* Change z-index to the lowest boundary of 1

As per review of @silverwind change the z-index to it's lowest requirement of 1.

* Change z-index to the lowest boundary of 1

As per review of @silverwind change the z-index to it's lowest requirement of 1.

* Revert changes made to wiki editor (unsticky) and add max-height

Fixes the max-height to 85vh, on the proposed 90vh it just came out just slightly too large.
Unstickies the changes from the sticky commits.

* Revert changes for the sticky title editor

Removes the changes as done by the sticky title editor.

* Add max-height definition to CodeMirror-scroll

Add the max-height definition for the CodeMirror-scroll class in order to generalize the changes spoken about in PR #18271

* Remove CodeMirror-scroll definition

Remove the max-height in CodeMirror-scroll definition, in order to generalize it in the CodeMirror less file. As per discussion in #18271.

* fine tune CodeMirror min-height/max-height

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

web_src/less/_base.less

@@ -2008,15 +2008,6 @@ table th[data-sortt-desc] {
   text-overflow: ellipsis;
 }
 
-.dropdown:not(.selection) > .menu.review-box > * {
-  @media (max-height: 700px) {
-    .CodeMirror,
-    .CodeMirror-scroll {
-      min-height: 100px;
-    }
-  }
-}
-
 .ui.dropdown .menu .item {
   border-radius: 0;
 }

web_src/less/_repository.less

@@ -1226,6 +1226,10 @@
         height: 200px;
         font-family: var(--fonts-monospace);
       }
+
+      .CodeMirror-scroll {
+        max-height: 85vh;
+      }
     }
   }
 
@@ -2107,6 +2111,10 @@
       }
     }
 
+    .form .CodeMirror-scroll {
+      max-height: 85vh;
+    }
+
     @media @mediaSm {
       .dividing.header .stackable.grid .button {
         margin-top: 2px;