Waldur-core

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- Improve performance of quotas timeline statistics API.
- Improved filters for alerts.
- Optimized query to Zabbix database for timeline stats.
- Fixed instance installation polling.
- Fixed OpenStack session initialization.
- Fixed documentation formatting.
- Fix tests for alerts.

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- Extended invoice generation with licensing data.
- Added ability to cancel alert acknowledgment.
- Added customers admin command for invoices creation.
- Added support for calculating monthly license usage.
- Documentation improvements.
- Test fixes.

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- Instance type is preserved on backup/restoration.
- Host IDs are now queried in Zabbix with a single call.
- UUID is now exposed at service projects list.

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- backup_source is now expoased in backup logging.
- Refactored price list synchronization with backend.
- Project admin and staff can now manage security groups and security group rules.
- Fix keystone session save and recover.
- Track keystone credentials instead of session itself.
- Implemented CPM security groups quotas.
- Logging improvements.
- Documentation improvements.

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- Issue status is now exposed over REST API.

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- Add endpoint for marking alerts as acknowledged.
- REST API for organization logo uploading.
- Added billing templates.
- Customer quotas are shown at customer endpoint.
- ProjectGroup viewset is now respecting user view permissions on project.
- Upgraded pysaml2 and djangosaml2 dependencies.
- Logging improvements.
- Bugfixes.