Update Agent.cs to filter logs using level

[jaffinito]

Describe the story, please be clear on scope of the story.

This is one possible approach:

newrelic-dotnet-agent/src/Agent/NewRelic/Agent/Core/Agent.cs

Lines 423 to 427 in 1a4fed5

	// we want to ignore case so that we don't have to normalize the deny-list values
	if (_configurationService.Configuration.LogLevelDenylist.Contains(normalizedLevel, StringComparer.OrdinalIgnoreCase))
	{
	return;
	}

Basically just add a .Contains using StringComparer.OrdinalIgnoreCase.

We want to avoid regex and wildcard to keep the logic simple and fast.

Add unit and integration tests. This could be updating existing tests to cover the new work or adding a new test completely.

Acceptance Criteria

• Existing and new unit tests pass
• Existing integration tests pass
• New integration tests pass

[workato-integration]

https://issues.newrelic.com/browse/NR-140886