Add 'ignore_other_package_versions' flag

[Yan-Yan98]

If True, only signatures for the versions specified under 'package_version'
are used. This includes all version-specific signatures and signatures
listed under an affected entry with that version.
In case no signatures exist for these versions for a certain CVE,
all signatures are used instead.

Example:
If there is at least one signature for the specified Android version
(let's say Android 13) for a CVE we ignore all signatures for other Android
versions (e.g. Android 14) as they are not relevant for us.
Using this flag we can ignore potential false-positives (e.g. patches for
Android version 14, if we already have a patch for our specific Android
version 13), while still being able to use data for newer Android
versions if there is no patch for our Android version.

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