[Rust-Axum] Allow use of array query params

[tanadeau]

This PR updates the rust-axum templates to do the following to support array query parameters:

1. Uses the Query extractor from axum_extra instead of axum as that supports extracting array query parameters
2. Use serde_html_form instead of serde_urlencoded for the same reason. Also the latter crate appears to be unmaintained. See https://docs.rs/serde_html_form/latest/serde_html_form/.
3. Updates the *QueryParams models based on guidance from above docs.

FYI: @frol @farcaller @richardwhiuk @paladinzh @jacob-pro

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[wing328]

thanks for the PR

cc @linxGnu

[wing328]

what about adding a config similar to those in https://github.com/OpenAPITools/openapi-generator/tree/master/bin/configs/manual to test array of query params (and commit the new samples)?

[linxGnu]

@tanadeau could you please explain why we need to remove vendorExtensions?

[tanadeau]

This created the wrong context, and within it, the template couldn't get the correct values for isArray, etc. It's now also consistent with the other blocks for header params, path params, etc. They would have had the same issue.

[linxGnu]

could you please also explain why we need to replace serde_urlencoded with serde_html_form?

[tanadeau]

serde_urlencoded explicitly doesn't support array query params and will never do so. See nox/serde_urlencoded#52 for example. serde_html_form is a fork with that in mind. See item 2 in the PR description.

[tanadeau]

what about adding a config similar to those in https://github.com/OpenAPITools/openapi-generator/tree/master/bin/configs/manual to test array of query params (and commit the new samples)?

I'll do that.

[tanadeau]

I believe I've addressed all comments.