Add 'Show on a map' button to Location in profile, fix layout (#26214)

Not too important, but I think that it'd be a pretty neat touch.

Also fixes some layout bugs introduced by a previous PR.

---------

Co-authored-by: Gusted <postmaster@gusted.xyz>
Co-authored-by: Caesar Schinas <caesar@caesarschinas.com>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

templates/user/settings/profile.tmpl

@@ -35,7 +35,7 @@
 				</div>
 				<div class="field">
 					<label for="location">{{.locale.Tr "settings.location"}}</label>
-					<input id="location" name="location"  value="{{.SignedUser.Location}}" maxlength="50">
+					<input id="location" name="location" placeholder="{{.locale.Tr "settings.location_placeholder"}}" value="{{.SignedUser.Location}}" maxlength="50">
 				</div>
 
 				<div class="divider"></div>