properly handle sources other than alphafold providing PLDDT confidence scores & shading from model quality score type response

Any structure with 'pLDDT' model quality score should get alphafold2-style shaded alphafold reliability annotation tracks via JAL-3895, and be ranked along side other alphafold2 scored sources.

See for example
>EPAS1_HUMAN/1-870 Endothelial PAS domain-containing protein 1
MTADKEKKRSSSERRKEKSRDAARCRRSKETEVFYELAHELPLPHSVSSHLDKASIMRLAISFLRTHKLLSS
VCSENESEAEADQQMDNLYLKALEGFIAVVTQDGDMIFLSENISKFMGLTQVELTGHSIFDFTHPCDHEEIR
ENLSLKNGSGFGKKSKDMSTERDFFMRMKCTVTNRGRTVNLKSATWKVLHCTGQVKVYNNCPPHNSLCGYKE
PLLSCLIIMCEPIQHPSHMDIPLDSKTFLSRHSMDMKFTYCDDRITELIGYHPEELLGRSAYEFYHALDSEN
MTKSHQNLCTKGQVVSGQYRMLAKHGGYVWLETQGTVIYNPRNLQPQCIMCVNYVLSEIEKNDVVFSMDQTE
SLFKPHLMAMNSIFDSSGKGAVSEKSNFLFTKLKEEPEELAQLAPTPGDAIISLDFGNQNFEESSAYGKAIL
PPSQPWATELRSHSTQSEAGSLPAFTVPQAAAPGSTTPSATSSSSSCSTPNSPEDYYTSLDNDLKIEVIEKL
FAMDTEAKDQCSTQTDFNELDLETLAPYIPMDGEDFQLSPICPEERLLAENPQSTPQHCFSAMTNIFQPLAP
VAPHSPFLLDKFQQQLESKKTEPEHRPMSSIFFDAGSKASLPPCCGQASTPLSSMGGRSNTQWPPDPPLHFG
PTKWAVGDQRTEFLGAAPLG-----PPVSPPHVSTFKTRSAKGFGARGPDVLSPAMVALSNKLKLKRQLEYE
EQAFQDLSGGDPPGGSTSHLMWKRMKNLRGGSCPLMPDKPLSANVPNDKFTQNPMRGLGHPLRHLPLPQPPS
AISPGENSKSRFPPQCYATQYQDYSLSSAHKVSGMASRLLGPSFESYLLPELTRYDCEVNVPVLGSSTLLQG
GDLLRALDQAT

3d-beacons now has a Levylab source providing oligomeric alphafold based structures - these should be ranked in the same way as alphafold and imported with alphafold quality scores.