chore: resources search point to shared ES instance [CHI-2827]

[GPaoloni]

This PR is a followup to #742 and https://github.com/techmatters/infrastructure-config/pull/377.

Description

This PR changes the resources search, making it point to the shared instance. This is done by using the env var (already provided to the HRM container) that points to the SSM parameter that contains the configuration.

NOTE: deploying this changes the resources search. We may want to hold merging this.

Checklist

• Corresponding issue has been opened
• New tests added
• Feature flags / configuration added

Verification steps

AFTER YOU MERGE

1. Cut a release tag using the GitHub workflow. Wait for it to complete and notify in the #aselo-deploys Slack channel.
2. Comment on the ticket with the release tag version AND any additional instructions required to configure an environment to test the changes.
3. Only then move the ticket into the QA column in JIRA

You are responsible for ensuring the above steps are completed. If you move a ticket into QA without advising what version to test, the QA team will assume the latest tag has the changes. If it does not, the following confusion is on you! :-P