* Reduce "testing" interfaces
* Use a callback instead of a generator for Deno.runTests()
* Default RunTestsOptions::reportToConsole to true
* Compose TestMessage into a single interface
All Deno runtime test files were moved to cli/js/tests/ directory.
It makes a clear distinction that cli/js/tests/ contains code
that is run under Deno runtime as opposed to code in cli/js/ which
is used to create bundle and snapshot with "deno_typescript".