* Port Junit assert to Truth in `com.google.gson.stream`
* Port Junit assert to Truth in `com.google.gson.regression`
* Port Junit assert to Truth in `om.google.gson.reflect`
* Port Junit assert to Truth in `com.google.gson.metrics`
* Port Junit assert to Truth in `com.google.gson.internal`
* Port Junit assert to Truth in `com.google.gson.internal.sql`
* Port Junit assert to Truth in `com.google.gson.internal.reflect`
* Port Junit assert to Truth in `com.google.gson.internal.bind`
* Port Junit assert to Truth in `com.google.gson.internal.bind.util`
* Port Junit assert to Truth in `com.google.gson.functional`
* Replaces `List.of` with `Arrays.asList` to grant legacy
* Simplify `==` asserts
* Simplify `.contain()` asserts + Minor fixes
* Simplify asserts
* Add CodeQL GitHub code scanning workflow
* Only compile main sources for code scanning
* Move test .proto files to test sources
`annotations.proto` also seems to be only relevant for tests because the test
explicitly registers them as extensions. By default the Proto adapter does not
consider them.
* Address some code scanning findings
* Fix some more findings
Created some serialization specific tests regarding custom serializers. Revised some tests to use toJsonTree for better asserts instead of string matching.