Add support for CertificateStoreLocation and CertificateThumbprint in connection strings

[hajekj]

Since .NET Core can deal with Windows's certificate store, it should be supported in connection string just like in full .NET Framework versions.

[bgrainger]

Looks like the X509Store class is available in netstandard1.3 and higher.

[hajekj]

I have started working on some basic implementation: https://github.com/TheNetworg/MySqlConnector will complete with tests and then submit a PR.

[hajekj]

Okay, I have the initial code working now. I added some basic tests for connection string parsing, not sure how to approach the test against certificate store itself - should it attempt to write testing certificate to the store and then use that for tests? Or simply write the function requiring the input through InlineData? Eg. CertificateStoreLocation and the thumbprint?

[hajekj]

@bgrainger What is the release schedule for this package on Nuget? Do you think it would be possible to make a new release containing this change?

[bgrainger]

Added in 0.43.0.