css: Visual fixes to message feed notice.
css: Visual fixes to message feed notice.

Fixes #23273

Removed height restriction to allow the box to grow when text wraps
to the next line.

Aligned wrapped lines to the text in the first line instead of the
icon.

zulip/zulip,zulip/zulip,zulip/zulip,zulip/zulip,zulip/zulip,zulip/zulip,zulip/zulip