Feature: use @component test in sql tests

[paullatzelsperger]

What this PR changes/adds

Adds the @ComponentTest annotation to all SQL-related tests.

Why it does that

Those tests are not unit tests (the use non-mocked collaborators such as H2) and therefore should only run when triggered explicitly to reduce test runtime on local machines.

Further notes

• I also added a short test summary to the root buildfile, which produces output such as

  -----------------------------------------------------------------
  |  Results: SUCCESS (32 tests, 32 passed, 0 failed, 0 skipped)  |  
  -----------------------------------------------------------------
  

Linked Issue(s)

Closes #1132

Checklist

• added appropriate tests?
• performed checkstyle check locally?
• added/updated copyright headers?
• documented public classes/methods?
• added/updated relevant documentation?
• added relevant details to the changelog? (skip with label no-changelog)
• formatted title correctly? (take a look at the CONTRIBUTING and styleguide for details)

[paullatzelsperger]

#1151 implements @marcgs's suggestion of moving the summary out to a plugin. whichever PR we merge first - the other must remove the code from the build file.