feat: proxy-rewrite plugin's execution phase should change from rewrite to access

[qihaiyan]

Description

According to the document

In APISIX, only the authentication logic can be run in the rewrite phase

proxy-rewrite isn't an authentication plugin, so should be run in the access phase

[shreemaan-abhishek]

the document is inaccurate here.

[kayx23]

@shreemaan-abhishek please suggest a fix or help opening a PR, thanks.

And update the title of this issue accordingly.

[qihaiyan]

According to the openresty's run phases, the proxy-rewrite is used to change the request to upstream, so i think change the proxy-rewrite's run phase to access phase is more suitable.

[shreemaan-abhishek]

please suggest a fix or help opening a PR, thanks.

I opened a PR.

[shreemaan-abhishek]

closing in favor of #10973