Schema: Support multi-line text inputs

[ewels]

It would be nice to support / differentiate text variables between simple one-line inputs and multi-line textareas in the schema. (See original request for support in Seqera Platform launch page).

Need to figure out what the best JSON schema syntax is first. Suggestions from Slack discussion:

1. minLength
2. New format type textarea
3. Using a pattern that includes zero or more \n newlines

Once we agree on such a flag we can detect it in the launch form and have an option / docs for it in the schema builder.

[mbosio85]

It would be great if the schema included an optional configuration to specify the desired height of the box (like rows) when defining multi-line text areas.
I can see a number of use cases where the text area can be small and others where it should be bigger for it to be useful.