New dashicons for Customizer icons

[celloexpressions]

So that we don't hold #28504 up for this, this ticket is for creating any new Dashicons that may be needed for Customizer sections and panels, once they support icons. This may include better icons for some of the current ones, such as Site Title and Tagline (think "Site Identity", which we'll eventually be renaming that to when we add favicons there).

Doesn't necessarily have to happen for 4.1, but it really should. Also a chance that Dashicons people like all of the ones that're proposed in #28504, in which case we can wontfix this.

[valendesigns]

Any ideas on what a site identity icon would look like?

[celloexpressions]

#28504 was maybelatered, so this is no longer relevant.