Convert samples from dotnet/extensions to doc articles

We are removing samples from dotnet/extensions. In case we want to convert any of them to samples in our docs, we can find the source in the commit history: https://github.com/dotnet/extensions/tree/75759edc975749e1a8c4198c0078755a1822eac8.

After looking through them, here's my take on whether they would be valuable:
Sample | Valuable? | Notes
-- | -- | --
MemoryCacheConcurencySample | no | Seems to just illustrate mem cache can handle concurrency.
MemoryCacheFileWatchSample | no | The sample illustrate using IChangeToken from a file provider in a memory cache a file provider. Suspect API docs should be sufficient
MemoryCacheSample | no | All basic mem cache functionalities are already documented.
ProfilingSample | no | This is a terrible sample, even for illustrating profiling.
SqlServerCacheConcurencySample| no | Seems to just illustrate SqlServer cache can handle concurrency.
RedisCacheSample | no | Basic usage of Redis cache is covered in docs.
SqlServerCacheSample | no | Basic usage of SqlServer cache is covered in docs.
Logging/SampleApp | no | Basic usage of Logging is covered in docs.
HttpClientFactorySample | yes | We don't seem to have a lot of documentation regarding Polly integration, this sample could be valuable when writing a doc on this topic.
GenericHostSample | marginal | Seems like all concepts are covered by our docs at: https://docs.microsoft.com/en-us/aspnet/core/fundamentals/host/generic-host?view=aspnetcore-3.1. However, there may be a few scenarios that are not explicitly illustrated in our docs such as externally controlled or windows service based generic host apps.
SampleMsmqHost | marginal | Though this is a more elaborate sample of generic host usage and illustrates the use of Msmq, it doesn't present any scenario that isn't covered by our docs.