Correct and simplify core typed array typings

[dead-claudia]

Fixes #45198 #15402 #45199 #38665 and makes fixes for a number of other typed array typings issues a lot easier. May also reduce memory usage somewhat for apps not using the DOM typings.

This also makes a few other assorted fixes, like with the final parameter to methods like .find and .map, to align better with the spec.

This only touches typings. I ran into errors with paths being too long (it's not even all that heavily nested), so I wasn't able to run tests. (I created this using a sparse checkout to work around that, and so I'm also relying on CI here to check my work.)

[ghost]

All CLA requirements met.

[gabritto]

For reference: some of the changes in this PR seem to overlap with #47278

[dead-claudia]

Note for reviewers: I did find this causes Node's Buffer#slice method to fail to type-check, but only the type definitions. If you disable lib checking, it'll still work as desired, but I felt this was worth calling out. (I tried doing this by adding an override for the slice as per this PR, so it might not reproduce from outright replacing it.)

[sandersn]

If you want to keep working on this change, I'll start running Definitely Typed tests after all the baseline tests pass.

[sandersn]

When I run tests, I see a lot of failures because these constructors are no longer available. How are they supposed to be made available after this change?

[dead-claudia]

Whoops. I'll re-add them.

I've since gotten WSL hooked up, so I should be able to run the tests before pushing my update.

Edit: I also almost forgot about this PR. 😅

[sandersn]

To help with PR housekeeping, I'm going to close this PR since it's pretty old now.