Tests - update test command to show failures

[ShaneBeee]

Description

This PR aims to fix the /sk test command that doesn't show failed tests.

NOTE:
Im not 100% sure this is the best way to do things, so Im open to feedback.

Part One:

When running /sk test something, it would show a test as passed even though there was a parse error.
Exhibit A:

Now you might be thinking "But Shane, you can see the error right there"
Yes, that is true, but if you run a bunch of tests, not as easy to see.
Also, it still shows the test as a pass, but in reality it didn't pass.
Exhibit B:
"Yay everything looks good...."

"Well, I shouldn't have scrolled up.

So to fix this, I created a custom log handler for testing, TestingLogHandler, and added in some stuff to actually log the parse errors for the tests.
Exhibit C:
"Yay, now I know my test[s] failed"

This also fixes them not showing up in the json file.

Part Two:

A lovely side effect of this test is that it also helps users easily spot parsing errors.
These were run with quickTest

BEFORE:

"What? Where are these errors? I need details 😢"

AFTER:

"Omg there it is... test... script... line and all, oh happy day 😃"

Part Three:

I gave the lists some hyphens, to make them look like lists, and add "none" when said list is empty.

Part Four:

This one is small:
}, TestMode.DEV_MODE ? 0 : 50);
Remove the delay starting the test environment if in DEV_MODE!

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Target Minecraft Versions: any
Requirements: none
Related Issues: #7399

[TheAbsolutionism]

I very much like this!