Provide --update-server command for ruby-lsp exec

[vicocamacho]

Motivation

Closes #3124

This PR adds a --update-server option to the ruby-lsp command to provide users with the ability to easy upgrade the gem's version and automatically use the correct env to perform the upgrade.

Implementation

I leveraged the existing SetupBundler class to pull the correct environment configuration and then I use that to run the bundle update command.

Automated Tests

I added one automated integration test to verify the execution.

Manual Tests

I have run some manual tests in my local machine.