The set-default command implemented.

[janosmurai]

Type Of Change

• New feature (non-breaking change which adds functionality)
• Bug fix (non-breaking change which fixes an issue)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Any modification in the test cases
• Any modification in the documentation

Checklist:

• I have read and followed the contribution guideline.
• I have checked to ensure there aren't other open Pull Requests for the same update/change.
• All the test cases pass and new modifications in the production code are 100% covered.
• I have made corresponding changes to the documentation.

Related Issue

Closing:
DEM-255

Description

The set-default command implemented.
The CLI command autcompletes for the installed Dev Envs.

How Has This Been Tested?

Tested on Ubuntu 22.04.