added authentication propagating listener

[markbanierink]

Added a listener that is registered after the ContextualizedServerCallListener. This lister propagates the Authentication from the grpc context to the spring security context. This way all spring security features can be used in all services.

[codecov]

Codecov Report

Merging #233 (b29dc60) into master (da062e1) will decrease coverage by 0.13%.
The diff coverage is 89.47%.

@@             Coverage Diff              @@
##             master     #233      +/-   ##
============================================
- Coverage     90.31%   90.17%   -0.14%     
- Complexity      210      211       +1     
============================================
  Files            38       38              
  Lines           888      906      +18     
  Branches         41       41              
============================================
+ Hits            802      817      +15     
- Misses           68       70       +2     
- Partials         18       19       +1     

Impacted Files	Coverage Δ
.../springboot/grpc/security/SecurityInterceptor.java	93.54% <89.47%> (-1.91%)	⬇️
...grpc/autoconfigure/consul/GrpcConsulRegistrar.java	90.69% <0.00%> (-2.33%)	⬇️

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[ST-DDT]

I would probably store the authentication in a field instead of getting it from the context, but thats only a matter of preference.

[jvmlet]

Thanks @markbanierink, will review this PR first thing after I'm back to office (~28.07)