Follow ups for user defined tools

[mvdbeek]

#19434 has been merged (🎉). At this point it is still a little rough along the edges and there's plenty of work to do to make this really awesome and user/admin friendly.

• A new Tool.tool_type (probably user_defined?) so that user defined tools can be addressed in job config and be routed to dedicated resources
• more tests
• more documentation
  • Publish UserToolSource schema for reference in tool developer documentation
  • Unify XML and YAML tool developer docs
• Write migration guide
• Write FAQ
• Live preview of tools
• Outline javascript libraries for common operations
• Templates for different types of tools
• Tool shed support
• Missing features
  • configfiles are not supported
  • Access to reference data is not supported
  • Access to metadata and metadata files (such as BAM indexes) is not supported
  • Access to the extra_files directory is not supported