chore: updated docs and Helm chart for release

[github-actions]

This PR prepares the docs and the Helm chart for IRS release 5.3.0. Please check whether everything was updated correctly. Once this PR is merged, you can draft a new release with the following Releasenotes.

### Added

- Added filtering by "createdOn", "validUntil" to paging endpoint for Policy Store API: `GET /irs/policies/paged`. #750
- Added autocomplete endpoint Policy Store API: `GET /irs/policies/attributes/{attribute}`. #750
- Added get and delete functionality for contract definitions eclipse-tractusx/traceability-foss#1190

### Fixed

- Access and Usage Policy Validation flow correction. #757
- GET /irs/policies and GET /irs/policies/paged return the configured default policies if no custom default policy is defined now. #734
- IRS Policy Validation does not accept subset of AND constraint any longer. #649

### Changed

- Replaced technical error message when trying to delete the configured default policy with a user-friendly message.
- Renamed EdcCreateContractDefinitionRequest to EdcContractDefinition because it's used for both get and post eclipse-tractusx/traceability-foss#1190


**Full Changelog**: https://github.com/eclipse-tractusx/item-relationship-service/compare/5.2.0...5.3.0