This commit introduces the possibility to mark tags in tag sidebar as face...

This commit introduces the possibility to mark tags in tag sidebar as face tags, if they are not already face tags.
Meaning, when one tag is selected and is no face tag, the context menu for it contains an properties action to set this
tag as face tag. If multiple tags are selected, the context menu contains the action to mark them as face tags if at
least one of the selected tags is no face tag.

The default option for filtering names for confirmation in people sidebar is set to true. Meaning, by default,
the suggested tags in line edit and tag tree are filtered to only be face tags.
The option can be unset in setup->misc->Show only face tags ... .

CCBUGS: 262168