rewrite: Implement uri query operations

[armadi1809]

@francislavoie This is my Initial take at #6096. This is still to be improved as only add, delete and set are implemented, but I wanted to get your initial feedback on the overall architecture of the solution before implementing the remaining operations.

[francislavoie]

Yeah, good start.Couple things I notice off the bat:

• I think it should support a block (i.e. braces) to do multiple operations with a single handler, similar to the header directive. I think that's already covered at the JSON level, just need to add the block Caddyfile parsing.

• We need to apply the replacer on the query values (and maybe the keys too? Probably doesn't hurt). Users are usually not going to use static values, more often than not it's going to be dynamic using placeholders.

[armadi1809]

@francislavoie, out of the list of operations in the issue, which ones you think we should add on top of what we have here at the moment?

[francislavoie]

I think rename would be good to have. The defaulting operation isn't necessary. Value replacement would also be good to have.

We don't have to implement those right away though, we can add them in a follow-up.

[armadi1809]

I just added rename. We can add replace later as it looked a little bit more involved (especially if we want to use regex like for the headers). Please let me know if any modifications are still necessary in this PR.

[mholt]

This is looking really good! :) Nice work. Just a couple nits from my first pass. Probably ready to move out of draft state.

[armadi1809]

@mholt Thanks for the round of review! All your feedback items should now be resolved. I also removed the draft status from the PR.

[armadi1809]

All the discussions above (except for the order of operations) should now be resolved.

[mholt]

I think this is good to go -- let's give it a shot! Nice work @armadi1809 :)