Create automatic tests and releases using GitHub CI/CD

[Danjoe4]

Tests should run on each new contribution to master. Releases should be built when a maintainer merges master into a dedicated "release" branch. Flexible on how we want to do releases, just let me know. Please assign to me.

[woodser]

In-built java tests are run with each new contribution to master. For example, https://github.com/haveno-dex/haveno/blob/master/core/src/test/java/haveno/core/util/FormattingUtilsTest.java

However, it doesn't run our full typescript test suite which tests end-to-end functionality of creating accounts, funding the wallet, posting offers, taking trades, etc. That's only run with haveno-ts CI, which always runs against this repo's master branch.

Merging master to a dedicated release branch could make sense. It's how monero-project is run.