Trigger realm icon upload by clicking on realm icon element itself
rather than having a big upload button and to match our user avatar UI.
Added new spinner over the icon element itself to show while
uploading realm icon.
Users are unable to modify organization's profile picture, but
disabled buttons for the same are being shown to the user on the
organization profile settings page. This commit removes those
buttons. The file realm-logo-widget.hbs renders those buttons only
if the user is an admin and realm_logo.js has been updated to allow
operations(like click) on the buttons only to admins.
This is in series of refactoring of code for realm logo settings.
Further, we will remove ids from the template as well and simply use
general classes (.day-settings and .night-settings) to identify to which
theme-mode particular element belongs i.e. day or night as we did in this
change.
- These ids will further be used to represent each section concisely and
deduplicating code.
- Also, removed `realm-night-logo-section` class as it was redundant.
When we add Plus, the first sentence should change to "Available on Zulip
Standard and Plus".
I copied the styling of .tip out of expediency, but it's also possible that
long term we'll want only 1 tip-like box styling.
The hover styling is a bit random, but I tried to copy other hover styles I
found in settings.scss.
Note that this renames .upgrade_realm_plan_type_suggestion to .upgrade-tip.