WebPositive: Don't display '...' icon when empty

* Conditionally add/remove fOverflowMenu to BookmarkBar when window
is resized or a bookmark is added/removed.
* Improve handling of large window size changes (e.g. zoom button)
which require moving multiple bookmarks to/from fOverflowMenu in a
single call to FrameResized.
* Fixes #17616.

Change-Id: Id3e991167ec8d7aa540dd0644749cad1612de293
Reviewed-on: https://review.haiku-os.org/c/haiku/+/5324
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>

WebPositive: call base class in BookmarkBar::FrameResized

Fixes #13067.

Change-Id: Ia40ef83ea3e9676c9884e011b758b85d6bd27fcd
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2102
Reviewed-by: waddlesplash <waddlesplash@gmail.com>

Some improbements to the bookmark bar

- Resolve symlinks to bookmarks so we display the icons for those
- Adjust the minimal height of the bar to make space for icons (if you
use a tiny font size)
- Do not allow the bookmark bar to show when it is empty

Update bookmark bar item BMessage on file rename.

The ref stored in the message must be replaced to point to the new file
name. Fixes #10962.

BookmarkBar: style fixes and some error checking.

Thanks to axel for reviewing.

Fix the build. Introduced in hrev47248.

Move overflowing items from bookmark bar to a menu.

Since the bookmark bar can now be resized smaller than the space needed
for the items, move items that don't fit in it to a menu, which is
always the last item in the BMenuBar.

Web+: move BookmarbKar to own file.

It's a bit long for an inline class, and I'm going to add more stuff to
it.

Update bookmark bar item BMessage on file rename.

The ref stored in the message must be replaced to point to the new file
name. Fixes #10962.

BookmarkBar: style fixes and some error checking.

Thanks to axel for reviewing.

Fix the build. Introduced in hrev47248.

Move overflowing items from bookmark bar to a menu.

Since the bookmark bar can now be resized smaller than the space needed
for the items, move items that don't fit in it to a menu, which is
always the last item in the BMenuBar.

Web+: move BookmarbKar to own file.

It's a bit long for an inline class, and I'm going to add more stuff to
it.