Parameters for manual pipelines

[arthurpro]

The Parameters feature introduces a flexible and dynamic way to manage environment variables for manual pipelines.

Key Features:

• Users can create, update, and delete parameters.
• Supports various parameter types, including boolean, string, text, password, single and multiple-choice options.
• Parameter values are configured during manual pipeline creation and passed as environment variables to the pipeline.
• Environment variables collapsible panel added to pipeline Config tab (see screenshots)

This PR is open for suggestions and improvements.

[qwerty287]

Whoa, thank you very much for your work! This closes #3326, right?

I'm personally not sure if it would be better to define these in the yaml files, but I also see some problems with this, e.g. it would be per-workflow then and we have to pre-fetch the yamls to get the parameters.

And just from a very short overview of your code: You don't need a migration to sync the model, that's handled inside already.

[arthurpro]

@qwerty287 yes, I looked at #3326 and I really wanted something similar to GitHub workflow inputs. but for that to work we would need to have woodpecker pipeline workflows fully loaded and parsed ahead of running a manual pipeline. that made me rethink the approach. And I found the least invasive and more elegant way to simply plug into existing Additional pipeline variables in the manual pipeline window.
Also I borrowed the idea of Parameters from Jenkins pipelines because I'm using Woodpecker while trying to go away from Jenkins.
Thanks for your feedback! I'll remove the migration.