perf: really, really stop nagle's algorithm

[howardjohn]

Take 4? This time I made it so its very very hard to forget

[keithmattix]

Nice!

[bleggett]

Yeah this is cleaner either way, no reason to let the handlers have the opportunity to not set this.

[istio-testing]

In response to a cherrypick label: #1062 failed to apply on top of branch "release-1.22":

Applying: perf: really, really stop nagle's algorithm
Using index info to reconstruct a base tree...
M	src/proxy.rs
M	src/proxy/inbound.rs
M	src/proxy/outbound.rs
M	src/proxy/pool.rs
Falling back to patching base and 3-way merge...
Auto-merging src/proxy/pool.rs
Auto-merging src/proxy/outbound.rs
Auto-merging src/proxy/inbound.rs
CONFLICT (content): Merge conflict in src/proxy/inbound.rs
Auto-merging src/proxy.rs
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
Patch failed at 0001 perf: really, really stop nagle's algorithm
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".

[istio-testing]

In response to a cherrypick label: new issue created for failed cherrypick: #1063