Introduce fixes and more rigorous tests for 'Show on a map' feature (#26803) (#27365)

Backport #26803 by @n0toose

This change introduces some fixes for my original PR
(https://github.com/go-gitea/gitea/pull/26214) and introduces some
additional tests so that such a regression does not happen again in the
future.

Co-authored-by: Panagiotis "Ivory" Vasilopoulos <git@n0toose.net>

routers/web/shared/user/header.go

@@ -32,6 +32,7 @@ func PrepareContextForProfileBigAvatar(ctx *context.Context) {
 
 	ctx.Data["IsFollowing"] = ctx.Doer != nil && user_model.IsFollowing(ctx, ctx.Doer.ID, ctx.ContextUser.ID)
 	ctx.Data["ShowUserEmail"] = setting.UI.ShowUserEmail && ctx.ContextUser.Email != "" && ctx.IsSigned && !ctx.ContextUser.KeepEmailPrivate
+	ctx.Data["UserLocationMapURL"] = setting.Service.UserLocationMapURL
 
 	// Show OpenID URIs
 	openIDs, err := user_model.GetUserOpenIDs(ctx, ctx.ContextUser.ID)

routers/web/user/profile.go

@@ -52,7 +52,6 @@ func userProfile(ctx *context.Context) {
 
 	ctx.Data["Title"] = ctx.ContextUser.DisplayName()
 	ctx.Data["PageIsUserProfile"] = true
-	ctx.Data["UserLocationMapURL"] = setting.Service.UserLocationMapURL
 
 	// prepare heatmap data
 	if setting.Service.EnableUserHeatmap {