This commit removes the "Remove" and "Unsubscribe" action buttons from
various tables and replaces them with icon buttons using the "close"
icon.
Additionally, previously the rows with and without a remove button had
different heights. This commit updates the fixed `px` values to `em`
units to ensure equal height for all rows, regardless of whether a
remove-subscription button is present.
Fixes: #34874.
Fixes#32706.
A user with permission to invite users should be able to subscribe users
to any of the default streams whether they have the permission to do so
or not for each of those default streams or not. This should only happen
in the invite code path, and not the subscribe code path.
This commit also adds the ability to pick and chose default streams if
you do not have the permission to subscribe to any other channels.
Before this, if you did not have the permission to subscribe any other
channels, only the checkbox to subscribe to all the default streams at
once was available to you.
For the stream pill typeahead, we don't show streams that the user
cannot subscribe other users to. For more details, see
https://chat.zulip.org/#narrow/channel/101-design/topic/can.20subscribe.20other.20users.20permission.20invite
Updates the "Related articles" sections after the revisions to the
channel permissions documentation, focusing on the articles in the
"Channel management" section of the help center.
