This introduce a new "secret" per-repository property of type password
as described by #121856.
A token or secret may be used by some non blender.org repositories.
This only shows for remote repositories and is shown in the
"Add Remote Repository" popup.
This commit doesn't implement sending to token to the server which will
be implemented separately.
Ref !121886
Co-authored-by: Dalai Felinto <dalai@blender.org>