[bug]: split_pem() misses new versions of intermediate files #27
Description
Right now it's hardwired to split a file ending in "intermediates.pem." This is fine in most cases for new imports that have different files names. But in situations where you have a new version of the same file, a counter will be appended and this function will just re-split the original and miss the new intermediates file. The only time I can imagine this happening is a reissue of intermediate certs due to a revoked CA. Rare indeed, but important.
Implementation
Every other split function begins by just extracting directly from the pkcs#12 file what it needs. split_pem() needs to run on an existing intermediates file ONLY after all the de-duplication logic has run. So the result of intermediate_dupe_check() needs to pass along the name of the either the new intermediates file that it did not delete.