Add Authorization Feature to AspNetCoreHealth

[jvonruden]

The issue or feature being addressed

AppMetrics/AppMetrics#366

Details on the issue fix or feature implementation

Add Authorization Feature to AspNetCoreHealth. Instead of implementing Authorization details in AspNetCoreHealth use dependency injection with IHealthAuthorizationFilter interface to allow the calling application to implement their own Authorization Mechanism. The HttpContext context is passed into the IHealthAuthorizationFilter Authorized method because the most likely scenario is the caller will want to check for an Authorization headers and secrets.

Confirm the following

• [X ] I have ensured that I have merged the latest changes from the dev branch
• [X ] I have successfully run a local build
• [X ] I have included unit tests for the issue/feature
• I have included the github issue number in my commits