Add show timestamp/seconds and fullscreen options to action page (#24876)

Part of #24728

- The timestamp shows local time and is parsed by `date.toLocaleString`;
- "show seconds" and "show timestamps" are mutually exclusive, and they
can be both hidden.


https://github.com/go-gitea/gitea/assets/17645053/89531e54-37b7-4400-a6a0-bb3cc69eb6f5

Update for timestamp format:

<img width="306" alt="Screen Shot 2023-05-25 at 09 07 47"
src="https://github.com/go-gitea/gitea/assets/17645053/2d99768d-d39c-4c9e-81a2-7bc7470399dd">

---------

Co-authored-by: silverwind <me@silverwind.io>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

web_src/js/svg.js

@@ -26,6 +26,7 @@ import octiconEye from '../../public/img/svg/octicon-eye.svg';
 import octiconFile from '../../public/img/svg/octicon-file.svg';
 import octiconFileDirectoryFill from '../../public/img/svg/octicon-file-directory-fill.svg';
 import octiconFilter from '../../public/img/svg/octicon-filter.svg';
+import octiconGear from '../../public/img/svg/octicon-gear.svg';
 import octiconGitBranch from '../../public/img/svg/octicon-git-branch.svg';
 import octiconGitMerge from '../../public/img/svg/octicon-git-merge.svg';
 import octiconGitPullRequest from '../../public/img/svg/octicon-git-pull-request.svg';
@@ -94,6 +95,7 @@ const svgs = {
   'octicon-file': octiconFile,
   'octicon-file-directory-fill': octiconFileDirectoryFill,
   'octicon-filter': octiconFilter,
+  'octicon-gear': octiconGear,
   'octicon-git-branch': octiconGitBranch,
   'octicon-git-merge': octiconGitMerge,
   'octicon-git-pull-request': octiconGitPullRequest,
@@ -132,7 +134,7 @@ const svgs = {
   'octicon-tag': octiconTag,
   'octicon-triangle-down': octiconTriangleDown,
   'octicon-x': octiconX,
-  'octicon-x-circle-fill': octiconXCircleFill
+  'octicon-x-circle-fill': octiconXCircleFill,
 };
 
 // TODO: use a more general approach to access SVG icons.

web_src/js/utils.js

@@ -60,7 +60,7 @@ export function parseUrl(str) {
 }
 
 // return current locale chosen by user
-function getCurrentLocale() {
+export function getCurrentLocale() {
   return document.documentElement.lang;
 }