[5.6] Hide filter bar when no filters so it doesn't show up in embed mode

[stacey-gammon]

Something else seems to hide it in non-embed mode, but this code is in
6.0 and onward, and does the trick.

Before:

After:

Fixes #13894 for 5.6.2

[nreese]

This change hides the Apply these filters GUI from displaying when filtering a multi-dimensional visualization in embedded mode.

In kibana, when a user clicks on a bar, the following is displayed

When a user clicks on a bar in embedded mode - nothing happens and the above GUI is not displayed.

[stacey-gammon]

Turns out we want the filter bar to always show up as it helps out accessibility, so going to abandon this (see #14076 for background). Has the added benefit of not backporting a PR that has errors anyway. Thanks for the detailed review @nreese, sorry for the waste of time.