Improve flex list UI (#26970)

1. There is already `gt-ac`, so no need to introduce `flex-item-center`
2. The `flex-item-baseline` and `.flex-item-icon svg { margin-top: 1px
}` seem to be a tricky patch, they don't resolve the root problem, and
still cause misalignment in some cases.
* The root problem is: the "icon" needs to align with the sibling
"title"
    * So, make the "icon" and the "title" both have the same height 
3. `flex-text-inline` could only be used if the element is really
"inline", otherwise its `vertical-align` would make the box size change.
In most cases, `flex-text-block` is good enough.


![image](https://github.com/go-gitea/gitea/assets/2114189/1b7acfc2-b1c7-4e9c-a983-2fa932026479)

---------

Co-authored-by: silverwind <[email protected]>
Co-authored-by: Giteabot <[email protected]>

Author: 3 people

templates/explore/user_list.tmpl

@@ -1,6 +1,6 @@
 <div class="flex-list">
 	{{range .Users}}
-		<div class="flex-item flex-item-center">
+		<div class="flex-item gt-ac">
 			<div class="flex-item-leading">
 				{{ctx.AvatarUtils.Avatar . 48}}
 			</div>

templates/org/member/members.tmpl

@@ -7,7 +7,7 @@
 		<div class="flex-list">
 			{{range .Members}}
 				{{$isPublic := index $.MembersIsPublicMember .ID}}
-				<div class="flex-item {{if $.PublicOnly}}flex-item-center{{end}}">
+				<div class="flex-item {{if $.PublicOnly}}gt-ac{{end}}">
 					<div class="flex-item-leading">
 						<a href="{{.HomeLink}}">{{ctx.AvatarUtils.Avatar . 48}}</a>
 					</div>

templates/org/team/members.tmpl

@@ -24,7 +24,7 @@
 				<div class="ui attached segment">
 					<div class="flex-list">
 						{{range .Team.Members}}
-							<div class="flex-item flex-item-center">
+							<div class="flex-item gt-ac">
 								<div class="flex-item-leading">
 									<a href="{{.HomeLink}}">{{ctx.AvatarUtils.Avatar . 32}}</a>
 								</div>
@@ -56,7 +56,7 @@
 				<div class="ui attached segment">
 					<div class="flex-list">
 						{{range .Invites}}
-							<div class="flex-item flex-item-center">
+							<div class="flex-item gt-ac">
 								<div class="flex-item-main">
 									{{.Email}}
 								</div>

templates/org/team/repositories.tmpl

@@ -28,7 +28,7 @@
 				<div class="ui attached segment">
 					<div class="flex-list">
 						{{range .Team.Repos}}
-							<div class="flex-item flex-item-center">
+							<div class="flex-item gt-ac">
 								<div class="flex-item-leading">
 									{{template "repo/icon" .}}
 								</div>

templates/repo/actions/runs_list.tmpl

@@ -6,7 +6,7 @@
 	</div>
 	{{end}}
 	{{range .Runs}}
-		<div class="flex-item flex-item-center">
+		<div class="flex-item gt-ac">
 			<div class="flex-item-leading">
 				{{template "repo/actions/status" (dict "status" .Status.String "locale" $.locale)}}
 			</div>

templates/repo/settings/branches.tmpl

@@ -41,7 +41,7 @@
 			<div class="ui attached segment">
 				<div class="flex-list">
 					{{range .ProtectedBranches}}
-						<div class="flex-item flex-item-center">
+						<div class="flex-item gt-ac">
 							<div class="flex-item-main">
 								<div class="flex-item-title">
 									<div class="ui basic primary label">{{.RuleName}}</div>

templates/repo/settings/collaboration.tmpl

@@ -7,7 +7,7 @@
 		<div class="ui attached segment">
 			<div class="flex-list">
 				{{range .Collaborators}}
-					<div class="flex-item flex-item-center">
+					<div class="flex-item gt-ac">
 						<div class="flex-item-leading">
 							<a href="{{.HomeLink}}">{{ctx.AvatarUtils.Avatar . 32}}</a>
 						</div>

templates/repo/settings/options.tmpl

@@ -774,7 +774,7 @@
 					</div>
 				</div>
 				{{if not .Repository.IsMirror}}
-					<div class="flex-item flex-item-center">
+					<div class="flex-item gt-ac">
 						<div class="flex-item-main">
 							{{if .Repository.IsArchived}}
 								<div class="flex-item-title">{{.locale.Tr "repo.settings.unarchive.header"}}</div>

templates/shared/issuelist.tmpl

@@ -1,10 +1,12 @@
 <div id="issue-list" class="flex-list">
 	{{$approvalCounts := .ApprovalCounts}}
 	{{range .Issues}}
-		<div class="flex-item flex-item-baseline">
-			<div class="flex-item-leading gt-ac">
+		<div class="flex-item">
+			<div class="flex-item-leading">
 				{{if $.CanWriteIssuesOrPulls}}
+				<div class="flex-item-icon">
 					<input type="checkbox" autocomplete="off" class="issue-checkbox gt-mr-4" data-issue-id={{.ID}} aria-label="{{$.locale.Tr "repo.issues.action_check"}} &quot;{{.Title}}&quot;">
+				</div>
 				{{end}}
 				<div class="flex-item-icon">
 					{{template "shared/issueicon" .}}
@@ -44,7 +46,7 @@
 						{{end}}
 						{{if .NumComments}}
 						<div class="text grey">
-							<a class="gt-no-underline muted flex-text-inline" href="{{if .Link}}{{.Link}}{{else}}{{$.Link}}/{{.Index}}{{end}}">
+							<a class="gt-no-underline muted flex-text-block" href="{{if .Link}}{{.Link}}{{else}}{{$.Link}}/{{.Index}}{{end}}">
 								{{svg "octicon-comment" 16}}{{.NumComments}}
 							</a>
 						</div>

templates/shared/secrets/add_list.tmpl

@@ -14,7 +14,7 @@
 	{{if .Secrets}}
 	<div class="flex-list">
 		{{range .Secrets}}
-		<div class="flex-item flex-item-center">
+		<div class="flex-item gt-ac">
 			<div class="flex-item-leading">
 				{{svg "octicon-key" 32}}
 			</div>