* Adding default and envVar resource. Initial commit
* Adding Create method for resource creation with default resource and relevant unit tests.
* Adding isNullOrEmpty check to env var value to remove redundant condition.
* TracerProviderBuilder now calls Resource.Create to get the default resource with EnvVar attributes as well
* The default reource now includes the attributes from env var as well. Refactoring unit tests for the same.
* Adding ResourceDetector interface and public methods to add attributes from default and env var resources
* Missed out new resource files. Adding
* adding some more tests
* Adding missing import
* Updating public api list
* Refactoring method name for new methods
* Making IResourceDetector and corresponding impl internal until spec is official about detectors
* Refactoring return
* Was using wrong Sdk in test. Fixed.
* Adding error handling to OtelEnvResourceDetector
Co-authored-by: Cijo Thomas <cithomas@microsoft.com>
Mikel Blanchard