GitLab

* Updated library_index.json for testing

* Use easyjson for parsing library_index

* Added benchmarks for json deconding.

Results:

$ go test -v -benchmem -bench BenchmarkIndexParsing github.com/arduino/arduino-cli/arduino/libraries/librariesindex
=== RUN   TestIndexer
--- PASS: TestIndexer (0.16s)
goos: linux
goarch: amd64
pkg: github.com/arduino/arduino-cli/arduino/libraries/librariesindex
cpu: Intel(R) Core(TM) i7-8550U CPU @ 1.80GHz
BenchmarkIndexParsingStdJSON
BenchmarkIndexParsingStdJSON-8                 5         214872730 ns/op          94.52 MB/s    58956539 B/op     418973 allocs/op
BenchmarkIndexParsingEasyJSON
BenchmarkIndexParsingEasyJSON-8               16          69215472 ns/op         293.42 MB/s    56162664 B/op     418966 allocs/op
PASS
ok      github.com/arduino/arduino-cli/arduino/libraries/librariesindex 4.442s

easyjson is 3x faster.

* Updated license check cache

* Added easyjson to package_index.json parser

* Allow easyjson to match tags in case-insensitive

See https://github.com/mailru/easyjson/pull/372

* Added easyjson generation task in Taskfile

* Added github action check

* Update .github/workflows/check-easyjson.yml
Co-authored-by: per1234 <accounts@perglass.com>
Co-authored-by: per1234 <accounts@perglass.com>