Add detection of non-autoinstalled apps to parallel-find.pl

[adehnert]

It may sometimes be useful to recognize even not autoinstalled applications. For example, this could allows us to:

• Determine what apps we don't currently support would be popular to support in the future
• Inform users of non-autoinstalled apps for which we have autoinstallers that the autoinstaller exists (so that they can switch to a nominally better supported version)

We concluded at the team meeting today that as long as this runs with only scripts-security-upd bits and the data remains not-world-readable, we consider this to be acceptable from a privacy perspective.

It is unclear how we would get signatures for applications or what applications we would check; presumably implementors could come up with a few.