Extract hls-test-utils

[berberman]

With the migration of plugins' tests from HLS's func-test to their own packages, the common stanza hls-test-utils will no loger be available in the pattern that tests of plugins were imported as sources into func-test. But there are still many common functions need to be shared. Therefore, this PR extracts Test.Hls.Util into a new package hls-test-utils, with some re-exported modules. Plugin test executables now can depend on this new package, rather than data-default, lsp-test, tasty-*, etc.

Moreover, this PR finishes the migration of eval plugin tests.

[jneira]

look really great, this was a necessary step, many thanks
we will have another package to maintain in hackage but I hope it will not change frequently (maybe if re-exported packages change?)

[jneira]

eval tests are failing in windows with Exception: Timed out waiting to receive a message from the server.
rerunning just if case (but i dont have many hopes)

[jneira]

I've tried the hls-eval-plugin test suite locally with no luck: 40 out of 50 tests failed (2379.28s)
Lots of timeouts, but

  Multi line comments, with the last test line ends without newline:                                  FAIL (7.11s)
    test\Main.hs:186:
    expected: "module TEndingMulti where\n\n-- Now trailing doctest is allowed:\n\n{- >>> 42\n>>> 54\n42\n54\n-}\n"
     but got: "module TEndingMulti where\n\n-- Now trailing doctest is allowed:\n\n{- >>> 42\n>>> 54\n<stderr>: hPutChar: invalid argument (invalid character)\n-}\n"
  Evaluate expressions in Plain comments in both single line and multi line format:                   FAIL
    Exception: Timed out waiting to receive a message from the server.
    Last message received:
    {
        "id": 2,
        "jsonrpc": "2.0",
        "error": {
            "message": "C:\\TEMP\\TPl7BFB.hs: hPutChar: invalid argument (invalid character)",
            "code": -32603
        }
    }