fix(command): add SortCategories field to sort help output for categories and their respective flags

[mahadzaryab1]

What type of PR is this?

• bug
• feature

What this PR does / why we need it:

• Previously, we were sorting the categories in the help output by default. This PR provides a configurable option to sort and does not sort by default.

(REQUIRED)

Which issue(s) this PR fixes:

This PR fixes #1914

Special notes for your reviewer:

• The help command moves to the bottom when SortCategories is set to false - is this okay?

Testing

• Added unit tests for the help command

Release Notes

(REQUIRED)

Added a field `SortCategories` that will sort the categories and their respective flags in lexicographical order when set to true. 

[dearchap]

@mahadzaryab1 can you fix the failing tests ?

[mahadzaryab1]

@mahadzaryab1 can you fix the failing tests ?

@dearchap the tests were flaky since the flags are held in a map and so the output is not deterministic when they are sorted. It looks like we can't have deterministic tests for the non-sorting case with the current setup unless we switch to an ordered map of some sort. Do you have any thoughts on how to proceed?