Add support for (and disambiguate) Jetbrains Legacy Binary

[sh41]

Jetbrains have introduced a Legacy Binary package which is not differenciated from the regular package:

for example:

$ jq '.[] | select((.version == "21.0.8b1038.71") and .java_version == "linux" and .release_type == "ga" and .features == [] and .architecture == "x86_64" and .image_type == "jdk") ' < jetbrains/all.json

gives

{
  "architecture": "x86_64",
  "features": [],
  "file_type": "tar.gz",
  "filename": "jbrsdk-21.0.8-linux-x64-b1038.71.tar.gz",
  "image_type": "jdk",
  "java_version": "linux",
  "jvm_impl": "hotspot",
  "md5": "434af87aa90eea549b1d42386d49849b",
  "md5_file": "jbrsdk-21.0.8-linux-x64-b1038.71.tar.gz.md5",
  "os": "linux",
  "release_type": "ga",
  "sha1": "91793da29e5c3490d505f79eed62c8dc483d1543",
  "sha1_file": "jbrsdk-21.0.8-linux-x64-b1038.71.tar.gz.sha1",
  "sha256": "d9f0f9b504882f7b49eda8a41d55f0becd56655e3d2cbc23401e29e4e03d8a02",
  "sha256_file": "jbrsdk-21.0.8-linux-x64-b1038.71.tar.gz.sha256",
  "sha512": "714b3d97fbf1dd6388a1b000ee881665b942370172f3e011b582ba5e6ad2f821b2902e7358f693159e13e901ec01083f69e53159e1db19e44ae98e506526ffac",
  "sha512_file": "jbrsdk-21.0.8-linux-x64-b1038.71.tar.gz.sha512",
  "size": 240582204,
  "url": "https://cache-redirector.jetbrains.com/intellij-jbr/jbrsdk-21.0.8-linux-x64-b1038.71.tar.gz",
  "vendor": "jetbrains",
  "version": "21.0.8b1038.71"
}
{
  "architecture": "x86_64",
  "features": [],
  "file_type": "tar.gz",
  "filename": "jbrsdk_lb-21.0.8-linux-x64-b1038.71.tar.gz",
  "image_type": "jdk",
  "java_version": "linux",
  "jvm_impl": "hotspot",
  "md5": "378f2c48c29692c0c60063f02a789682",
  "md5_file": "jbrsdk_lb-21.0.8-linux-x64-b1038.71.tar.gz.md5",
  "os": "linux",
  "release_type": "ga",
  "sha1": "1e7c4ff8f5b5609eb3f11df67283f8cf52fb54a7",
  "sha1_file": "jbrsdk_lb-21.0.8-linux-x64-b1038.71.tar.gz.sha1",
  "sha256": "6eea4447474b7216ef86c6337d8cf799997a587bd27468481e09eafb42af122b",
  "sha256_file": "jbrsdk_lb-21.0.8-linux-x64-b1038.71.tar.gz.sha256",
  "sha512": "e7cc9bd25de8c4427d265828f581ad7c412c579b29ef7719c2699fffe4aa99d1cb24934d5adba52f93052b404e37e16a78d6d7fa8d464f0859247521739c0adc",
  "sha512_file": "jbrsdk_lb-21.0.8-linux-x64-b1038.71.tar.gz.sha512",
  "size": 493007542,
  "url": "https://cache-redirector.jetbrains.com/intellij-jbr/jbrsdk_lb-21.0.8-linux-x64-b1038.71.tar.gz",
  "vendor": "jetbrains",
  "version": "21.0.8b1038.71"
}

note the lb in the filename. Only the filename & checksums differ in the JSON payload for each. This relates to a change in the build process:
https://youtrack.jetbrains.com/issue/JBR-8317

see https://github.com/JetBrains/JetBrainsRuntime/releases/tag/jbr-release-21.0.8b1038.71 where they are labelled with (Legacy Binary).

[joschi]