Fix UI for release tag page / wiki page / subscription page (#25948)

Agenda:
This PR contains UI fixes for release tag page / wiki page /
subscription page.
Here is the list of changes made in this PR.
1. Release tag page
a. In the New Release page the whole ui got change. Now it is covering
in full page page with mobile view port. Description about the release
the editor preview now has a min-height. and the check boxes for
`Prerelease` and option are left aligned. Couple of divider are added.

2. Subscription page: 
a. In the subscription page the ui was distorted in mobile view. Now its
fix. Couple of unused styles were removed.

3. Create Wiki page:- 
a. In the page the preview of markdown is now contains a fix min-height
so this it will not distorted in desktop view and a divider is added
before action buttons. Couple of unused styles were removed.

# Before

## Release page

<img width="1391" alt="image"
src="319dec2e-08cf-40c5-920a-d651930ee28e">

<img width="494" alt="image"
src="03249f40-2d36-4552-bb93-43832aac2f8b">

<img width="1390" alt="image"
src="bf8b2d31-4857-480b-abd9-66a3ae6e24d8">

<img width="484" alt="image"
src="c3a58210-a337-4c8e-89a6-edb3975986bb">

Editor 
<img width="958" alt="image"
src="3bdd299d-d12b-4774-ace9-7184b1a57b18">

Editor preview
<img width="1293" alt="image"
src="2b61c528-c018-4800-ab86-07aae56adecd">

<img width="484" alt="image"
src="ff7bc5ee-9dc0-4f78-a0b1-94277ab27700">

#### After
<img width="1439" alt="image"
src="94f7e073-5977-40bd-98ef-0711ed0815cc">

<img width="1384" alt="image"
src="83e3105f-c1ee-4329-b90f-8bb724dac50f">
<img width="1440" alt="image"
src="05f024a5-52eb-4072-8599-d6ca12f6fad1">
<img width="1387" alt="image"
src="c73f069b-572a-4a13-aaa9-fc5b4dd3420d">

<img width="1440" alt="image"
src="2f98f012-8e64-4a12-9595-5acdef18f85c">

Markdown preview change
<img width="1368" alt="image"
src="31e583ec-48f6-4f1a-8b56-0164fcb127a5">


Wiki page

Before
<img width="1393" alt="image"
src="9c9cfdf6-3c2a-4f47-883b-76624d96f9a0">
<img width="499" alt="image"
src="522ad573-1ad2-4fa2-8bf7-48a3dded14e7">


Preview of mark down. 
<img width="488" alt="image"
src="998f3c25-9fca-43c8-b1ff-648aab291727">

Footer 
<img width="490" alt="image"
src="89c6cf4e-4599-4403-bac8-285efdd9361a">

After

<img width="1389" alt="image"
src="1ee0fc72-f864-44c0-b2e4-e0e8a8470204">
<img width="498" alt="image"
src="b35b9a5d-8e26-4869-a6ed-6cef1f4a87a6">
<img width="499" alt="image"
src="b40bcbaa-fca6-42ab-9556-f950811b565d">

Preview tab block has min-height 
<img width="1392" alt="image"
src="4a53d6c2-596c-423a-91b1-533cef734f93">


Mobile view
<img width="496" alt="image"
src="c5ffc4c9-3c21-4cad-bc32-2ea3f0644a08">

<img width="497" alt="image"
src="08dd560f-4333-41ec-95b9-8154910d2254">
<img width="496" alt="image"
src="9fba8f55-727b-4756-a4a6-2070c719b15b">



## Subscription page

### Before

<img width="1393" alt="image"
src="0a7d561b-f56c-4ebe-93bd-952abecd437f">

<img width="492" alt="image"
src="4dc44d0c-ea81-4130-8afb-8f271c029e8a">

After
<img width="1394" alt="image"
src="a3567e30-2b5b-49d6-9ecb-2ab481ea4d36">


<img width="494" alt="image"
src="024da9e2-dfc4-4672-95cc-a6ac034d9712">

<img width="508" alt="image"
src="b748ecea-427c-4f8b-a1bf-08f82f9a42e6">

web_src/css/repo/release-tag.css

@@ -132,3 +132,7 @@
 .repository.new.release .field .attachment_edit {
   width: 450px !important;
 }
+
+.repository.new.release .markup {
+  min-height: 240px;
+}

web_src/css/repo/wiki.css

@@ -9,6 +9,7 @@
 
 .repository.wiki .markup {
   overflow: visible;
+  min-height: 340px;
 }
 
 .repository.wiki .wiki-content-parts .markup {