[bug#69593] Add FluidPlug

[paul via Guix-patches via <guix-patches@gnu.org>]

Hi gabber!

Thank you for your detailed feedback, it was very helpful. I hadn't 
considered cross compilation at all so thank you for bringing that up. I 
was not able to cross compile the plugins for aarch64 since fluidsynth 
itself is currently failing to cross compile, but I setup the package 
for cross compilation and I was able to build with 
--system=aarch64-linux the following store paths:

/gnu/store/3hczja8j7108mj4k3m304bbn8m4law15-fluidplug-fluidsynthpads-lv2-0.0.5-0.38d7d0d
/gnu/store/iniwffhk57184w1sdkvpks41ggddm7ns-fluidplug-fluidsynthleads-lv2-0.0.5-0.38d7d0d
/gnu/store/d06c2g7szd5qs81fc74m9gyb7qbyl9q8-fluidplug-fluidsynthfx-lv2-0.0.5-0.38d7d0d
/gnu/store/hlhgmppf2kj2vhqvs27s3nhb692xspkk-fluidplug-fluidstrings-lv2-0.0.5-0.38d7d0d
/gnu/store/iqwgsxm2y0mi5pm9sk0r5pdysiv9nh5z-fluidplug-fluidsoundfx-lv2-0.0.5-0.38d7d0d
/gnu/store/fyap3ah75mb08zbrlp6swx2avg4gm1n1-fluidplug-fluidreeds-lv2-0.0.5-0.38d7d0d
/gnu/store/k0xlhswwbk6k7lsfgdxmpxpil4mjy8z4-fluidplug-fluidpipes-lv2-0.0.5-0.38d7d0d
/gnu/store/g6gzpri28ns9p8a87mzgwwgppl5m5ina-fluidplug-fluidpianos-lv2-0.0.5-0.38d7d0d
/gnu/store/f3aiv82b6gz6pjkl5nq3kllrqpk85q0j-fluidplug-fluidpercussion-lv2-0.0.5-0.38d7d0d
/gnu/store/h3i4sry66zwndanfqf756142bjh4i2r8-fluidplug-fluidorgans-lv2-0.0.5-0.38d7d0d
/gnu/store/y440smx317wxihf4r86fa62xsxic676b-fluidplug-fluidguitars-lv2-0.0.5-0.38d7d0d
/gnu/store/64grrbvqi737mn12nr1ipm49zvaif93x-fluidplug-fluidethnic-lv2-0.0.5-0.38d7d0d
/gnu/store/jvizy86991z00vqzm53apbc7dy83y6c3-fluidplug-fluidensemble-lv2-0.0.5-0.38d7d0d
/gnu/store/2wbfswji4j7pjyzwbvqm0dg36cm98q7g-fluidplug-fluiddrums-lv2-0.0.5-0.38d7d0d
/gnu/store/zxkz8zp4mih4l9cbnwwmf9i4snqddwny-fluidplug-fluidchromperc-lv2-0.0.5-0.38d7d0d
/gnu/store/nq4ml9kay8gg7n16jns8xjwbjd459xlg-fluidplug-fluidbrass-lv2-0.0.5-0.38d7d0d
/gnu/store/nmk6m917irzyflnhvv160s8m9js7q2vn-fluidplug-fluidbass-lv2-0.0.5-0.38d7d0d
/gnu/store/sc3aywx99yf2shyv5j28hz4dyldf8cs5-fluidplug-fluidgm-lv2-0.0.5-0.38d7d0d
/gnu/store/xvc3ga0ai95hdmxsmvmlal23myqs2mjh-fluidplug-red-zeppelin-5-lv2-0.0.5-0.38d7d0d
/gnu/store/zd95nyvkaajai6qqld685h15gi4l2bia-fluidplug-red-zeppelin-4-lv2-0.0.5-0.38d7d0d
/gnu/store/5f4gavfvvx43dka1qrby7816fpvzl1a7-fluidplug-black-pearl-5-lv2-0.0.5-0.38d7d0d
/gnu/store/dr4ldfyjrq7y6271d693n3gjmcnkh64s-fluidplug-black-pearl-4b-lv2-0.0.5-0.38d7d0d
/gnu/store/gf5prac2pfzlrgazwxjcb46pz7n9hdr1-fluidplug-black-pearl-4a-lv2-0.0.5-0.38d7d0d
/gnu/store/0vk83yfs6305r47rpcmiv2yhzrnb2lz5-fluidplug-avl-drumkits-perc-lv2-0.0.5-0.38d7d0d
/gnu/store/nlbkhbnp4d0sakmh1vlpiiz4cqri998j-fluidplug-airfont320-lv2-0.0.5-0.38d7d0d
/gnu/store/7lf14xbcv7k11wp17rfqaxnanyn7045l-fluidplug-lv2-0.0.5-0.38d7d0d


I should have addressed all of your comments, please let me know if you 
have any further feedback. I'm sending a rev4. Thank you!

cheers

giacomo