Switches to better BATS asserts

[potiuk]

BATS has additional libraries of asserts that are much more
straightforward and nicer to write tests for bash scripts

There is no dockerfile from BATS that contains those, so we
had to build our own (but it follows the same structure
as #9652 - where we keep our dev docker image
sources inside our repository and the generated docker images
in "apache/airflow:-CALVER-TOOLVER format.

We have more BATS unit test to add - following #10576
and this change will be of great help.

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[potiuk]

CC: @OmairK - I am also going to add more and more unit tests for the bash functions of Breeze. This PR makes it super-easy to write and run new tests, so you might want to give it a try :). BATS provides a very nice framework to test bash functions - and in this PR I also added https://github.com/bats-core/bats-assert and https://github.com/bats-core/bats-support and https://github.com/bats-core/bats-file which provide a really structured and straightforward way to write asserts (assert output of a function, whether a file exists, whether the function failed or succeeded and the like).

It's rather easy to write new tests:

• you add a "<file_to_test>.bats" in tests/bats_tests.

• Then you write tests similar to:

setup() {
  load bats_utils
  # any common initiali`ztion goes here
}

teardown() {
  # any common teardown goes here
}

@test "Test missing value for a parametert" {
    export _BREEZE_ALLOWED_TEST_PARAMS="a b /c"

  run parameters::check_and_save_allowed_param "TEST_PARAM"  "Test Param" "--message"
  assert_output "
ERROR:  Allowed Test Param: [ a b c ]. Is: ''.
Switch to supported value with --message flag."
 assert_failure
}

the test above runs parameters::check_and_save_allowed_param without TEST_PARAM value set and the method fails with the expected error message..

[potiuk]

Others - with this one and few other changes implemented recently (and follow up tests)- our Bash scripts will become almost as good as structured python code :)

[potiuk]

All green, just quarantine tests failed :)

[potiuk]

Would love to get that in, so I can add more unit tests while adding the "Google Shell guidelines" compatibility :)

[potiuk]

Thanks @kaxil!