Introduce primitives to control internal log level

[Scottmitch]

Motivation:
ServiceTalk can generate logs internally. These logs are either at a
fixed level hard coded by ServiceTalk devs, or taken dynamically at the
time of creation based upon the logging configuration. The first
approach is too ridged and may not be appropriate for the application's
logging level filtering (e.g. trace logs are never logged, or go against
logging configuration policies), or take the log level at a snapshot in
time which doesn't allow for practical filtering (e.g. log level may
start at OFF, and be switched to non-OFF value later when debugging, and
ThresholdFilters are not commonly used and introduce performance
overhead because isEnabled() pre-checks will succeed resulting in
wasted string building).

Modifications:

• Introduce a way to explicitly configure the logging level for
  interesting cases (e.g. wire logging, h2 frame logging, zipkin logging
  reporter)
• Introduce a way to avoid logging user data for wire logging and h2
  frame logging so it can be enabled in production.

Result:
Primitives exits such that Applications can more explicitly control the
log level used internally by ServiceTalk.

[Scottmitch]

build failure attributed to #1200

test this please

[idelpivnitskiy]

Then we can reuse LoggerConfig here as well to make configuration consistent.

[idelpivnitskiy]

Thanks!
A few more suggestions, then LGTM:

[idelpivnitskiy]

requireNonNull(loggerName)?

[Scottmitch]

I'll let LoggerFactory.getLogger enforce this.

[Scottmitch]

build failure attributed to #1200

test this please