feat: display version at startup

[dmacvicar]

This PR is a request to add version when starting up the server. It is the less intrusive way that I thought of, without moving parts of cmd/version around.

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immudb 0.9.2
Commit  : 36738cd16d8d020c99ef121e57791fc401c4e65e
Built by: xxxxxxxx@codenotary.com
Built at: Wed, 19 May 2021 18:50:51 CEST
================ Config ================
Data dir         : /dev/shm/immu4
Address          : 0.0.0.0:3322
Metrics address  : 0.0.0.0:9497/metrics
Config file      : configs/immudb.toml
Max recv msg size: 33554432
Auth enabled     : true
Dev mode         : false
Default database : defaultdb
Maintenance mode : false
...

[coveralls]

Coverage decreased (-0.04%) to 87.585% when pulling 3ff5182 on feat/display_version into 57500de on master.