refactor(volo-build): adapt to the codegen backend new trait and new codegen context defined in pilota-build

[Ggiggle]

Change-Id: I79680ac8fd6b4b657aa965f45c850a461bcc3ab4

Motivation

We do some refactor for pilota-build in cloudwego/pilota#344 to solve the problem of maintainability.

Solution

Adapt to the new trait and struct defination.

[codecov]

Codecov Report

❌ Patch coverage is 11.66667% with 53 lines in your changes missing coverage. Please review.
✅ Project coverage is 43.42%. Comparing base (22d0d88) to head (e3ee355).
⚠️ Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
volo-build/src/grpc_backend.rs	0.00%	34 Missing ⚠️
volo-build/src/thrift_backend.rs	0.00%	12 Missing ⚠️
volo-grpc/src/codec/encode.rs	36.36%	7 Missing ⚠️

❌ Your patch status has failed because the patch coverage (11.66%) is below the target coverage (70.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #626      +/-   ##
==========================================
+ Coverage   41.96%   43.42%   +1.46%     
==========================================
  Files         160      160              
  Lines       19806    19355     -451     
==========================================
+ Hits         8311     8405      +94     
+ Misses      11495    10950     -545     

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[PureWhiteWu]

这里保留一下原有的样式吧，看着原来那么拆分是故意的；或者改成下面这样：

Suggested change

	"client",
	"server", # core
	"http1",
	"http2", # protocol
	"query",
	"form",
	"json", # serde
	"tls", # https
	"cookie",
	"multipart",
	"ws", # exts
	# core
	"client",
	"server",
	# protocol
	"http1",
	"http2",
	# serde
	"query",
	"form",
	"json",
	# https
	"tls",
	# exts
	"cookie",
	"multipart",
	"ws",

[Ggiggle]

ok 这个是自动 fmt，我关掉