First pass at basic query string parameters.

[mitchdenny]

First pass at basic string binding for request delegate source generator

This PR gets the basics of binding strings to the source generated request delegate. It builds on the special type parameter handling. The PR includes logic to detect the IFromX metadata interfaces and set the parameter type accordingly (this is the explicit handling logic discussed.

It includes partial null handling in that it will return a 400 if StringValues is null or empty - but it doesn't do full on nullability handling around things like nullable arrays, arrays of nullables, and nullable arrays of nullables.

You can see where I've got a pattern matching switch to detect what kind of parameter preparation logic to emit. The idea here is that if we have a particular special case which is messy to handle with just one block of code we can use this switch to provide alternative implementations, but mostly it'll just switch on the Source property.

(note: some tests aren't passing yet because I haven't updated the baselines - that'll be the last thing I do)

[mitchdenny]

@captainsafia here is the minimal PR that I think will help us avoid stepping on each others toes.

[wtgodbe]

Please undo the submodule changes

[captainsafia]

LGTM for the generator changes

It looks like there have been some unintended changes made to the git submodules. I'd revert those before merging.

[captainsafia]

Approving since I'm fine with the generator changes and @wtgodbe has already requested changes for the submodule changes I was nervous about. 😅

[mitchdenny]

Please undo the submodule changes

Done. Sorry about that. GitHub was giving me issues yesterday not recognizing a push that I had made, and I did a sloppy whitespace change and ended up pulling in the submodules update inadvertently.

[dougbu]

Please undo the submodule changes

Done. Sorry about that. GitHub was giving me issues yesterday not recognizing a push that I had made, and I did a sloppy whitespace change and ended up pulling in the submodules update inadvertently.

git config --global --add submodule.recurse true works wonders and will affect all future aspnetcore clones you make.