Fix zap contextual logging naming

[mabdh]

Is your feature request related to a problem? Please describe.
The contextual logging with zap in salt is inside log package. Getting zap log from context would be log.FromContext(ctx) and return Zap. Since log has multiple possible logger (logrus & zap), this would be confusing.

Describe the solution you'd like
Add more specific identifier for Zap logger specific function to make it clearer.
log.FromContext > log.ZapFromContext
log.WithFields > log.ZapContextWithFields