Remove spaces from CmdData::get_str(). Fixes #2925

[AlesKus]

Related Issue(s)	nasa/fprime#2925
Has Unit Tests (y/n)	y
Documentation Included (y/n)	n

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Change Description

Removed " ".join from CmdData::get_str().
Added some simple unit tests to ensure it works.

Rationale

Fix nasa/fprime#2925.

Testing/Review Recommendations

Same as in the issue description:

1. Run the Ref example
2. Execute a command with a string argument
3. Look at command.log

There should be no spaces in the args section.

Future Work

N/A

[LeStarch]

I think this change is an improvement. It does rely on each argument converting cleanly to a string. So we will need to watch on complex types to ensure they work correctly.

[LeStarch]

Works as expected with complex types.