Sigma-cli

What's Changed
Breaking Changes
* Added plugin system: backends and pipelines must now be installed with the new `sigma plugin` command group. Currently only some backends are available but will be migrated soon. If you rely on not yet migrated backends or pipelines, please keep using 0.5.x until this is done.

Other
* Fix: Error in Wrong Pipeline Checker by sifex in https://github.com/SigmaHQ/sigma-cli/pull/9
* Some minor formatting changes by andurin in https://github.com/SigmaHQ/sigma-cli/pull/12

New Contributors
* sifex made their first contribution in https://github.com/SigmaHQ/sigma-cli/pull/9
* andurin made their first contribution in https://github.com/SigmaHQ/sigma-cli/pull/13

**Full Changelog**: https://github.com/SigmaHQ/sigma-cli/compare/v0.5.3...v0.6.0

* Added `field_name_prefix_mapping` transformation.

* Fix: crash while validation of certain SigmaString values.

What's Changed
* Add __name__== "__main__" condition on the main cli file by Res260 in https://github.com/SigmaHQ/sigma-cli/pull/5
* Added rule validation by thomaspatzke in https://github.com/SigmaHQ/sigma-cli/pull/6

New Contributors
* Res260 made their first contribution in https://github.com/SigmaHQ/sigma-cli/pull/5
* thomaspatzke made their first contribution in https://github.com/SigmaHQ/sigma-cli/pull/6

**Full Changelog**: https://github.com/SigmaHQ/sigma-cli/compare/v0.5.0...v0.5.1

* Check if processing pipeline is required for target.
* Check if used pipelines are intended for usage with target.
* Input rules must be specified for conversion.
* Breaking change: pipelines in sigma.cli.pipelines is now a dict of pipeline definitions. Resolver moved to pipeline_resolver.

* Fixes from pySigma.
* Improved error handling.
* Display of collected errors after conversion result.