Improve the version handling

Description

The other day I was reading about how to add a version flag in Go and remembered that the current way to update the version flag sucks, so I went ahead and implemented what I read on the article adding some minor improvements for my use case.

Changes:

• There's a new --version flag which behaves exactly like the version command
• If dblab is installed using go install, the command's output will be like this dblab version v0.26.0
• If installed using brew or directly downloading the files in the release, the output will be the same as above
• If build locally, the output will show the latest commit revision dblab version rev: b7b59ff

References:

• 3 Easy Ways To Add Version Flag in Go
• Using the main.version ldflag](https://goreleaser.com/cookbooks/using-main.version/)
• Getting a --version flag for Cobra CLIs in Go

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Tested it using different scenarios.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• I have checked my code and corrected any misspellings