[checked-c-convert] Porting Tool Updates

[rchyena]

This PR adds several new features to checked-c-convert, including NT_array detection.

[Machiry]

Overall, this looks great! Great work!

I have some changes that I've requested:

• There's a space appearing after the itype constraint when it is added: `f(int * : itype(_Ptr) ). Could you remove it? The output of the tool is much nicer to read.

✅ Fixed.

• The new code often uses maybe 30 characters a line for comments, spacing the comment across multiple lines. That is hard to read. The clang line limit is 80 characters. Could you take advantage of that and have longer lines?

✅ Fixed.

• There were a number of typos in the comments that I pointed.

✅ Fixed. I used a spell checker this time :)

• The formatting for if statements is still off in the new code that you've written. There are a number of places where you wrote if(, and a space needs to be placed after the if . I pointed a few out, and left many more for you to fix.

✅ Fixed. I used a format checker this time.

There are markdown files for Checked C in clang\docs\checkedc. Could you create one that capture the content that you posted about the algorithm in the conversion tool? That was really helpful for me. If you want, you can post it later as a separate commit. I just want to make it gets documented).

📚 Created one.

[dtarditi]

Looks great! Thank you!