fix: Console logging is inconsistent between Agent and Profiler

[tippmar-nr]

Fixes #2939.

Modifies and optimizes logging behavior in the agent as follows:

NEW_RELIC_LOG_ENABLED	NEW_RELIC_LOG_CONSOLE	newrelic.config	Result
1	0	<log enabled="true" />	File logging is enabled. Console logging is disabled. This is the default configuration.
1	1	<log enabled="true" console="true" />	File and audit logging is disabled. Console logging is enabled.
0	n/a	<log enabled="false" />	All logging output is disabled (includes file, audit, event log and console).

Notes:

• When logging is disabled, we configure a SilentLogger which is an empty implementation of the Serilog.ILogger interface. We also set the log level to off, which will short-circuit nearly all calls to the public methods in Logger.
• Configuration in newrelic.config remains unchanged
• Audit logging can be enabled in newrelic.config via <log enabled="true" auditLog="true" />

Profiler logging already follows this behavior so no changes were required.

Does not include tests; behavior was manually verified.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 92.00000% with 2 lines in your changes missing coverage. Please review.

Project coverage is 81.80%. Comparing base (ee0dd2b) to head (cced557).

Files with missing lines	Patch %	Lines
.../NewRelic/Agent/Core/Logging/LoggerBootstrapper.cs	92.00%	0 Missing and 2 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2955      +/-   ##
==========================================
- Coverage   81.80%   81.80%   -0.01%     
==========================================
  Files         470      470              
  Lines       29949    29953       +4     
  Branches     3327     3330       +3     
==========================================
+ Hits        24499    24502       +3     
  Misses       4658     4658              
- Partials      792      793       +1     

Flag	Coverage Δ
Agent	82.75% <92.00%> (-0.01%)	⬇️
Profiler	73.13% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
.../NewRelic/Agent/Core/Logging/LoggerBootstrapper.cs	77.57% <92.00%> (+1.79%)	⬆️

... and 1 file with indirect coverage changes