[WIP] feat(rpc): supports middleware responses

[yusukebe]

Fixes #2719

I'm not sure if it can be resolved.

The author should do the following, if applicable

• Add tests
• Run tests
• bun run format:fix && bun run lint:fix to format the code
• Add TSDoc/JSDoc to document the code

[github-actions]

Bundle size check

	main (5149aa4)	#4252 (eec6286)	+/-
Bundle Size (B)	18,206B	18,206B	0B
Bundle Size (KB)	17.78K	17.78K	0K

Compiler Diagnostics (tsc)

	main (5149aa4)	#4252 (eec6286)	+/-
Files	262	262	0
Lines	116,387	116,387	0
Identifiers	114,406	114,406	0
Symbols	259,900	259,900	0
Types	162,566	162,566	0
Instantiations	3,039,295	3,039,295	0
Memory used	272,210K	277,575K	5,365K
I/O read	0.02s	0.02s	0s
I/O write	0s	0s	0s
Parse time	0.66s	0.84s	0.18s
Bind time	0.28s	0.32s	0.04s
Check time	3.9s	3.89s	-0.01s
Emit time	0s	0s	0s
Total time	4.84s	5.05s	0.21s

Compiler Diagnostics (typescript-go)

	main (5149aa4)	#4252 (eec6286)	+/-
Files	232	232	0
Lines	106,286	106,286	0
Identifiers	106,146	106,146	0
Symbols	371,532	371,532	0
Types	293,008	293,008	0
Instantiations	3,568,491	3,568,491	0
Memory used	229,848K	229,674K	-174K
Memory allocs	10,003,567	10,003,530	-37
Parse time	0.077s	0.073s	-0.004s
Bind time	0.032s	0.023s	-0.009s
Check time	1.377s	1.444s	0.067s
Emit time	0s	0s	0s
Total time	1.488s	1.542s	0.054s

---

Reported by octocov

[github-actions]

HTTP Performance Benchmark

Framework	Runtime	Average	Ping	Query	Body
hono (origin/main)	bun	37,046.56	51,015.48	32,116.33	28,007.86
hono (current)	bun	37,149.82	50,748.80	32,876.25	27,824.42
Change		+0.28%	-0.52%	+2.37%	-0.65%