Add and apply InfluxDB related flags

[trinhdn2]

Prerequisite

• [ ] https://github.com/BuildOnViction/tomochain/pull/428

Changelog

• [X] Add standalone metrics HTTP server listening, apart from the previous pprof endpoint: --metrics.addr. --metrics.port
• [X] Add configurable InfluxDB connection flags:
  • General: --metrics.influxdb.endpoint, --metrics.influxdb.tags
  • V1 only: --metrics.influxdb, --metrics.influxdb.database, --metrics.influxdb.username, --metrics.influxdb.password,
  • V2 only: --metrics.influxdbv2, --metrics.influxdb.token, --metrics.influxdb.bucket, --metrics.influxdb.organization