Remove assert.New and require.New

[lkowalick]

Remove assert.New and require.New from the codebase.

[ZenGround0]

I don't like it but will not block.

[travisperson]

Whats the reason for not wanting to use assert.New and require.New?

[acruikshank]

Here are a few justifications for this PR:

1. Defining a variable that shadows the package is bad practice.
2. using assert.New and require.New is adding hundreds of lines to our test code.
3. We're doing it wrong in many of our tests. If you include a t.Run within a test you must define new assert and require for a new value of t, but we often use the assert and require in closure scope. Using it incorrectly makes our tests unsafe under parallelization (I fixed a lot of this in our flaky test phase). Using these correctly adds a lot of boilerplate when you're trying to write a lot of quick, idiomatic, well documented test cases off an existing setup.
4. The people that established this convention are no longer on the project. I was never given any explanation for why we standardized on the OO versions of this code. If we default to the functional style, there will be nothing wrong with using the OO style occasionally (though I challenge you to provide a reason beyond the extra 3 characters in the assertions).
5. It's tedious. Writing a test you start by adding the assert.New, then you start writing your test and realize you need a require, so you go back up and add the require.New, then you realize that you want all requires so you have to go up and delete the assert.New. It's a really small amount of effort, but it's a small amount of effort multiplied over a whole lot of testing. This is a great place to reduce friction.

This is something I've been wanting to propose for a long time.

[travisperson]

Okay sounds good. @rkowalick can you update the title and description?

[shannonwells]

I'm a fan. Having tried it, it doesn't help much to rename the import to something else (I've used ast and req). In my current branch where I'm also (because of this PR) replacing everything by just calling <assert|require>.NoError(t, err) explicitly, it makes for cleaner code with fewer lines, and also, I don't create requires just to send to mustDoAThing type functions.

[acruikshank]

Little green 't, 's will be floating past my vision as I close my eyes tonight, but it all looks in order.