Feature/environment multi

[otherNet]

Fixes #1888, Fixes #1696.

The implementation goes in the same line as the PR 1822 and it is possible to install directly this one because this solution includes the solution for that issue too.
In order to discriminate data stored to the database it has been introduced a different database name per each couple <GUARDIAN_ENV, HEDERA_NET>.
In this way the user will be able to use the same infrastructure and maintain their data referring to different Hedera network and different Guardian Ecosystem Environment completely separated from each other

The global .env contains the only variable: GUARDIAN_ENV.
it introduces the variable PREUSED_HEDERA_NET to let specify the hedera net already in use.
.env example:
      GUARDIAN_ENV=develop

it add the new PREUSED_HEDERA_NET variable in each service environment both in the .env and .env.docker files
      # configure this variable only at first installation of the release
       PREUSED_HEDERA_NET=testnet

Change db name in the db-helper.ts common library introducing parametric name of the kind:
${process.env.ENV}${process.env.HEDERA_NET}${process.env.DB_DATABASE}
The dbName variable is set by a ternary operator to keep current database name unchanged and maintain the already created database and data unchanged.

More docs are provided at:
- https://github.com/IntellectEU/guardian/blob/feature/environment_Multi/docs/environments/persistance-configuration-according-environment.md

Related issue(s):

Fixes #1888, #1696.

Notes for reviewer:

Checklist

• Documented (Code comments, README, etc.)
• Tested (unit, integration, etc.)