RFR: 6695: Build agent as part of checkin tests

[Marcus Hirt]

Also adding formatting checks. Seems the integrations tests are failing on Windows, so only running unit tests for now
on Windows. Will open a new issues on that.

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Commit messages:
 - Only unit tests on Windows for now
 - Windows fix
 - Fixing formatting scripts
 - Adding running tests
 - 6695: Build agent as part of checkin tests - first step, formatting

Changes: https://git.openjdk.java.net/jmc/pull/127/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jmc&pr=127&range=00
  Issue: https://bugs.openjdk.java.net/browse/JMC-6695
  Stats: 428 lines in 39 files changed: 102 ins; 83 del; 243 mod
  Patch: https://git.openjdk.java.net/jmc/pull/127.diff
  Fetch: git fetch https://git.openjdk.java.net/jmc pull/127/head:pull/127

PR: https://git.openjdk.java.net/jmc/pull/127