[radar-push-endpoint] Allow backfill configuration

[mpgxvii]

Description of the change

• Allow enabling or disabling of push endpoint backfill requests

TODO: Additional configs for backfill

Benefits

• Currently this is part of the config of push endpoint but we are not able to specify this in the helm chart

Possible drawbacks

Applicable issues

• fixes #

Additional information

Checklist

• Chart version bumped in Chart.yaml according to semver.
• Variables are documented in the README.md
• Title of the PR starts with chart name (e.g. [<name_of_the_chart>])

[github-actions]

Great PR! Please pay attention to the following items before merging:

Files matching charts/*/values.yaml:

• Is the PR adding a new container? Please reviewer, add it to the models (internal process)
• Is the PR adding a new parameter? Please, ensure it’s documented in the README.md

This is an automatically generated QA checklist based on modified files.