Consume SSL certs provided as VCAP ENV var for secure db connection

[Skretzschmann]

Description

Previously service instances which provide SSL certificates via VCAP ENVs could not be consumed and had to be manually added to the config.
This PR allows for the SSL cert to be read from the VCAP ENVs provided by the service instance for establishing a secure connection.

Motivation and Context

This change allows for ease of use when utilising service instance that provide SSL certs via VCAP ENVs.

How Has This Been Tested?

Unit tests have been added.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• Docs update
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have followed the guidelines in CONTRIBUTING.md, including the required formatting of the commit message

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: Skretzschmann / name: Samuel Kretzschmann (b9bed42)