Helm: Allows to configure client_max_body_size and location blocks

[panzouh]

What this PR does / why we need it:

Adjusting client_max_body_size in Nginx could allow me fixing nginx errors client intended to send too large body.
Adjusting location snippets would allow me to add custom headers on individual endpoints, ensuring tailored optimizations where needed.

Which issue(s) this PR fixes:
Fixes #10521

Special notes for your reviewer:

Checklist

• Reviewed the CONTRIBUTING.md guide (required)
• Documentation added
• Tests updated
• CHANGELOG.md updated
  • If the change is worth mentioning in the release notes, add add-to-release-notes label
• Changes that require user attention or interaction to upgrade are documented in docs/sources/setup/upgrade/_index.md
• For Helm chart changes bump the Helm chart version in production/helm/loki/Chart.yaml and update production/helm/loki/CHANGELOG.md and production/helm/loki/README.md. Example PR
• If the change is deprecating or removing a configuration option, update the deprecated-config.yaml and deleted-config.yaml files respectively in the tools/deprecated-config-checker directory. Example PR

[CLAassistant]

All committers have signed the CLA.

[github-actions]

Trivy scan found the following vulnerabilities:

• HIGH openssl: Incorrect cipher key and IV length processing in libcrypto3 v3.1.3-r0. Fixed in v3.1.4-r0
• HIGH openssl: Incorrect cipher key and IV length processing in libssl3 v3.1.3-r0. Fixed in v3.1.4-r0

[JStickler]

Please note this bullet from the checklist: For Helm chart changes bump the Helm chart version in production/helm/loki/Chart.yaml and update production/helm/loki/CHANGELOG.md and production/helm/loki/README.md. Example PR

You need to update the chart version in ALL of the files listed above.