Cherry-pick #17378 to 7.x: [Metricbeat] Add a switch to the driver definition on SQL module to use pretty names

[sayden]

Cherry-pick of PR #17378 to 7.x branch. Original message:

What does this PR do?

SQL module directly passes the driver name to the sqlx library. This must match the library name used in Metricbeat: mysql for MySQL, postgresql for PostgreSQL but godror for Oracle which is ugly in terms of UX.

Why is it important?

Docs shouldn't fix UX issues so this PR fixes this in code.

Checklist

• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have made corresponding change to the default configuration files
• I have added tests that prove my fix is effective or that my feature works
• I have added an entry in CHANGELOG.next.asciidoc or CHANGELOG-developer.next.asciidoc.

How to test this PR locally

• Launch Oracle Docker Image

docker run --name oracle -d -p 1521:1521 store/oracle/database-enterprise:12.2.0.1

• Configure SQL module as follows. Metricbeat will need to be configured to use Oracle driver as follows https://www.elastic.co/guide/en/beats/metricbeat/current/metricbeat-module-oracle.html:

# Module: sql
# Docs: https://www.elastic.co/guide/en/beats/metricbeat/7.7/metricbeat-module-sql.html

- module: sql
  metricsets:
    - query
  period: 10s
  hosts: ["oracle://sys:Oradoc_db1@172.17.0.2:1521/ORCLPDB1.localdomain?sysdba=1"]

  driver: "oracle"
  sql_query: "SELECT TABLESPACE_NAME, TABLESPACE_SIZE, ALLOCATED_SPACE, FREE_SPACE FROM DBA_TEMP_FREE_SPACE"
  sql_response_format: table

• An event is generated with the driver name oracle

[elasticmachine]

Pinging @elastic/integrations-services (Team:Services)