code lens: migrate test code lenses to use gopls-based code lens

[hyangah]

gopls implements various code lenses golang/go#36787
and run test, ... are one of those already available. They are currently disabled due to
conflicts with our own code lenses which offer better integration at this moment.

@mcjcloud implemented a logic to intercept gopls codelenses and swap their commands
with the extension's native commands. Start to use the feature.
That allows us to utilize gopls to determine the right place to place those code lenses,
and avoid issues like #482.