43764: storage: change command registration to declare if ro/rw r=irfansharif a=irfansharif

This PR reworks parts of #26916. It's not strictly necessary, but is a
quality of life improvement. There are also miscellaneous cleanups
around TeeEngine, RocksDB benchmarks, etc.

Previous to this we relied on engine.NewReadOnly's runtime panics when
receiving writes to ensure that read-only commands do not accidentally
write data. By changing the command registration process to have
commands declare upfront whether they are read-only or read-write, we
can plumb in engine.Reader or engine.ReadWriter respectively. It's nice
rely on the type system to assert these guarantees.

NB: There's still the unaddressed wart that is replica read code paths
operating off an engine.ReadWriter. Changing this out would require a
refactor of replica evaluation code paths, which I'm not doing now. This
PR however paves the way for that.

Release note: None


43779: pgwire/hba: fix the HBA parser r=knz a=knz

Previously, the HBA rule parser would not properly support the pg
split format for separate address and netmask.

When the 4th column of a rule in
the setting `server.host_based_authentication.configuration` is
an IP address, the 5th column is expected to be an IP netmask.

Prior to this patch, the HBA parser would not recognize the netmask
syntax and instead expect a simple number of bits set (which is not
valid pg syntax).

This patch fixes this and adds the corresponding tests.

Additionally, this patch replaces the HBA rule parser by one inspired
from pg's own implementation, so as to ease future maintainance.

Release note (bug fix): When the 4th column of a rule in the setting
`server.host_based_authentication.configuration` is an IP address
without a mask length (e.g. `1.2.3.4` instead of `1.2.0.0/16`),
CockroachDB now properly interprets the 5th column as an IP netmask,
as per https://www.postgresql.org/docs/current/auth-pg-hba-conf.html.

Co-authored-by: irfan sharif <irfanmahmoudsharif@gmail.com>
Co-authored-by: Raphael 'kena' Poss <knz@thaumogen.net>

43792: batcheval: clean up remaning variable names of `{Reader,ReadWriter}` types r=irfansharif a=irfansharif

Ignore first commit, reviewed in #43764. 

We should be using {reader,readWriter} for
{Reader,ReadWriter} respectively instead. I'd skipped everything under
batcheval when working on #43265, back when I thought it'd be a good
idea to plumb in an engine.Batch throughout replica read codepaths. Due
to perf penalty as seen on #43388, I'm no longer going to be doing that.
This is the remaining work.

Release note: None


43811: hba: stricter parsing and better pretty-printing r=knz a=knz

The following defects were found by @mjibson using
`go-fuzz` (#43805) and are fixed by this patch:

- the code would parse then fail to pretty-print an empty connection
  type and auth method.
- the code would parse then pretty-print incorrectly a connection
  type or auth method containing commas or other special characters.
- the code would accept an empty string as address.
- the code would accept then fail to pretty-print columns containing
  special (control) characters.

Note that the code previously supported tabs (\t) and carriage
returns (\r) inside quoted strings, and this is now rejected. For most
fields, this does not matter, as these special characters were not
valid semantically anyway.

However, for the method options in the last column it is theoretically
possible for a method to wish to use such special characters. This is
not currently the case for the CCL `gss` method already implemented,
so this change is not introducing a regression. A comment is left in
the code to indicate what needs to be changed if a future method needs
this support.

Release note (security): CockroachDB now properly rejects control
characters in the value of the cluster setting
`server.host_based_authentication.configuration`. These characters
were previously accepted and would silently yield rules matching
differently from intended. Deployments careful to strip control
characters from their HBA configuration are not affected.

Co-authored-by: irfan sharif <irfanmahmoudsharif@gmail.com>
Co-authored-by: Raphael 'kena' Poss <knz@thaumogen.net>