Add string.Left/string.Right

[thecraftianman]

Just a couple more string library tests I wrote up real quick while testing.

[sarahsturgeon]

Couple of updates to the expected err message! 🙏

[thecraftianman]

Should be good now

[sarahsturgeon]

last thing 🙏

[sarahsturgeon]

Weird batch of errors on the latest run, dunno why it's doing that

[thecraftianman]

Yeah that's really strange. I don't think there's anything else wrong with the test cases themselves as far as I can tell. Does it still do that even if the tests are run again?

[sarahsturgeon]

I think the error message just says ? instead of Left/Right - idk why it does that but it's probably a simple fix