feat: add new keyInfo fields in line with latest redis-timeseries return values

[wolfwfr]

Proposed Change

This change introduces the following fields to the client.Info(key) response:

• totalSamples
• memoryUsage
• sourceKey
• firstTimestamp
• chunkType

which should be in line with the TS.INFO response of the latest version of the redis-timeseries module.

Testing

• The change has been verified against docker images redislabs/redistimeseries:latest, as well as redislabs/redistimeseries:1.0.0.
• All unit tests succeed.