feat: support for specifiying custom filters for split,scale,crop,pad

[grusell]

When doing hardware encoding, it can be desirable to use hardware filters for split, scaling, cropping and padding. This commits add support for specifying replacements for the standard filters in a profile. It is required that the filter specified supports the parameters used by encore.

Pull Request Template

Description

Please include a summary of the change and which issue is fixed or added. Please also include relevant motivation and context. List any dependencies that are required for this change.

Fixes #(issue)

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

This has been tested by manually running jobs with hw filters defined in filter settings.

Checklist:

• [X ] I confirm that I wrote and/or have the right to submit the contents of my PR, by agreeing to the Developer Certificate of Origin (see https://github.com/svt/open-source-project-template/blob/master/docs/CONTRIBUTING.adoc[docs/CONTRIBUTING]).
• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code in hard-to-understand areas
• [] I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules
• PR has an informative and human-readable title
• Changes are limited to a single goal (no scope creep)
• Code can be automatically merged (no conflicts)