[bitnami/wordpress] Add externalDatabase.ssl to add client flag --ssl-mode=REQUIRED

[migruiz4]

Description of the change

Adds new value externalDatabase.ssl (already existing in bitnami/ghost chart) that sets the env variable MYSQL_CLIENT_ENABLE_SSL.
This env variable allows users to configure the database client with the flag --ssl-mode=REQUIRED.

Applicable issues

• fixes Mysql Error in SELECT 1, using Azure Mysql #29087 (without extraEnvVars)

Checklist

• Chart version bumped in Chart.yaml according to semver. This is not necessary when the changes only affect README.md files.
• Variables are documented in the values.yaml and added to the README.md using readme-generator-for-helm
• Title of the pull request follows this pattern [bitnami/<name_of_the_chart>] Descriptive title
• All commits signed off and in agreement of Developer Certificate of Origin (DCO)

[github-actions]

This Pull Request has been automatically marked as "stale" because it has not had recent activity (for 15 days). It will be closed if no further activity occurs. Thank you for your contribution.

[github-actions]

Due to the lack of activity in the last 5 days since it was marked as "stale", we proceed to close this Pull Request. Do not hesitate to reopen it later if necessary.