Log Pomelo version in info output

[lauxjpn]

The following log output should also contain the Pomelo version:

info: Microsoft.EntityFrameworkCore.Infrastructure[10403]
      Entity Framework Core 3.1.8 initialized 'Context' using provider 'Pomelo.EntityFrameworkCore.MySql' with options: ServerVersion 5.7.0 MySql SensitiveDataLoggingEnabled DetailedErrorsEnabled

Either we can implement this for Pomelo, or the EF Core team can implement this for providers in general.

[ajcvickers]

@lauxjpn Seems like a good idea for providers in general. Would you mind filing an issue on efcore?

[lauxjpn]

@ajcvickers Done!