Introduce shared template for search inputs (#25338)

- Set
[type=search](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input/search)
- Disable spellcheck
- Set maxLength 255 that I found in `templates/repo/issue/search.tmpl`
- Remove unnecessary `max-width`, it does nothing

---------

Co-authored-by: delvh <dev.lh@web.de>
Co-authored-by: Giteabot <teabot@gitea.io>

web_src/js/components/DashboardRepoList.vue

@@ -16,7 +16,7 @@
       </h4>
       <div class="ui attached segment repos-search">
         <div class="ui fluid right action left icon input" :class="{loading: isLoading}">
-          <input @input="changeReposFilter(reposFilter)" v-model="searchQuery" ref="search" @keydown="reposFilterKeyControl" :placeholder="textSearchRepos">
+          <input type="search" spellcheck="false" maxlength="255" @input="changeReposFilter(reposFilter)" v-model="searchQuery" ref="search" @keydown="reposFilterKeyControl" :placeholder="textSearchRepos">
           <i class="icon gt-df gt-ac gt-jc"><svg-icon name="octicon-search" :size="16"/></i>
           <div class="ui dropdown icon button" :title="textFilter">
             <svg-icon name="octicon-filter" :size="16"/>