Fix long project name display in issue list and in related dropdown (#23653)

This PR is to fix the second problem mentioned in #23625, along with the
long texts problem in `issue-item-bottom-row` of `issuelist.tmpl`

Main changes are:
1. Add `max-width` to the search dropdowns in issue list and make the
possible long texts inside to show ellipsis if texts are long
2. Adjust the conditions in
[issuelist.tmpl](https://github.com/go-gitea/gitea/blob/1d35fa0e784dffcadacb2322a3d7ac3ec2ff89b2/templates/shared/issuelist.tmpl#L146-L167)
to fix the problem as mentioned by the
[comment](https://github.com/go-gitea/gitea/issues/23625#issuecomment-1479281060)
3. Use `word-break: break-word;` in `issue-item-bottom-row` to break the
possible long texts.

After the PR
issuelist in repo (similar for pr list):
<img width="366" alt="截屏2023-03-23 17 42 40"
src="https://user-images.githubusercontent.com/17645053/227163953-93e9adbd-5785-4c16-b538-9db901787775.png">

dropdowns with long name (Here take reference from github to deal with
the long names cases: show ellipsis with no title, because all these
options are clickable, and it might not be necessary to add titles to
them ):

<img width="370" alt="截屏2023-03-23 17 43 50"
src="https://user-images.githubusercontent.com/17645053/227164215-df6fcaaa-9fee-4256-a57c-053fbcffafbb.png">

<img width="365" alt="截屏2023-03-23 17 43 56"
src="https://user-images.githubusercontent.com/17645053/227164227-9c99abcd-f410-4e07-b5b8-cbce764eedcd.png">

issue page (similar for pr page):
<img width="374" alt="截屏2023-03-23 17 45 37"
src="https://user-images.githubusercontent.com/17645053/227164668-654a8188-dac8-4bbf-a6e3-f3768a644a1b.png">

on PC:
<img width="1412" alt="截屏2023-03-23 17 47 20"
src="https://user-images.githubusercontent.com/17645053/227166694-e7bcc6e5-9667-4cef-9fbf-db85640a2c6c.png">

<img width="1433" alt="截屏2023-03-23 17 46 40"
src="https://user-images.githubusercontent.com/17645053/227165182-4e2a5d19-74bc-4c66-b73c-23cbca176ffe.png">

web_src/css/helpers.css

@@ -197,6 +197,7 @@
 
 .gt-content-center { align-content: center !important; }
 
+.gt-shrink-0 { flex-shrink: 0 !important; }
 .gt-whitespace-nowrap { white-space: nowrap !important; }
 
 @media (max-width: 767px) {

web_src/css/repository.css

@@ -143,7 +143,8 @@
 
 .repository .filter.menu .menu {
   max-height: 500px;
-  overflow-x: auto;
+  max-width: 300px;
+  overflow-x: hidden;
   right: 0 !important;
   left: auto !important;
 }

web_src/css/shared/issuelist.css

@@ -84,6 +84,7 @@
 
 .issue.list > .item .desc a {
   color: inherit;
+  word-break: break-word;
 }
 
 .issue.list > .item .desc .time-since,