Add a new type of validation for defining a pipeline_id

[ph]

The current validation when defining a pipeline_id is really minimal, I should say non-existent, we accept everything that can be coerced to a string. This means the following string identifier are valid pipeline_id.

• 1
• 2pipeline
• 3pipeline####!
• 😴🙄🤔🤥
• hola (space at the end of a string)

I think we should do the following:

• Limit the possible charsets to lowercase a-z, hyphens, numbers.
• Create a concrete type that the Java code and the settings validator can use.
• Refactor the config management to use that type
• strip whitespace at the end and beginning.
• Derive an Array type from the concrete type, (id must be unique)
• Maybe accept any characters that a uuid v3 can accept? This will make it more compatible with GUI tools.

[jsvd]

an interesting issue on this kind of problem from elasticsearch: elastic/elasticsearch#9059