Support declarative config for contrib extensions

[zeitlinger]

• Declarative config: support inferred spans opentelemetry-java-contrib#2011
• declarative config: support gcp auth extension opentelemetry-java-contrib#2012
• declarative config: span stacktrace opentelemetry-java-contrib#2028
• declarative config: baggage processor opentelemetry-java-contrib#2013
• Declarative config: Cloud component providers opentelemetry-java-contrib#2014
• declarative config: support Span stacktrace opentelemetry-java-contrib#2262

[zeitlinger]

closing as all items are added to the project directly