7.0.0 - Multiple Provider support

Multiple provider support (using provider factory)
Performance improvement in provider initialization stage.
Update libraries to latest version.

Code breaking changes - Rename default configuration settings in appsettings.json (new settings - AzureBlobStorageConfig, AmazonS3Config, GoogleCloudStorageConfig, FileSystemStorageConfig)
Code breaking changes - Core service name changed to AmazonS3Service, AzureBlobStorageService, GoogleCloudStorageService, FileSystemStorageService (Read ducument on GitHub)

Bug fixed - Could not load file or assembly 'LiteX Storage Core'