only split after first colon when doing an override

[mikemhenry]

Description

Allows users to specify an override like --override foo:bar:baz to be split into foo and bar:baz instead of foo bar baz which would break our parser. Common use case is to have a url as a key, ie some_path:http://s3.aws.com

Motivation and context

Resolves #1060

How has this been tested?

Tested locally.

Change log

Fixes bug where if a `:` was in a key, we could not override the arguement in our perses-cli. 

[codecov]

Codecov Report

Merging #1062 (045eeb3) into main (c4368a6) will decrease coverage by 1.78%.
The diff coverage is 100.00%.

[ijpulidos]

This looks good to me, thanks. We might want tests for the CLI or the functions it uses to parse the arguments in the future, I'm thinking on extending the CLI to include the benchmarks so it might be not worth it now. LGTM!