Support `patternProperties` for data/samplesheet validation

Hi,

I would like to validate a csv file that has dynamic columns that are generated based on some sample identifier.

Example CSV file (input.csv):

fieldA, sample1, sample2, sample3,
rowA, 1, 2, 3,
rowB, 4, 5, 6

In JSON schema, I cannot use the regular items.properties to describe these columns because they can change between runs.
Instead I am using the items.patternProperties to validate fields based on regex match (csv_schema.json):

{
    "$schema": "https://json-schema.org/draft/2020-12/schema",
    "title": "my title",
    "type": "array",
    "items": {
        "type": "object",
        "patternProperties": {
            "^sample": {
                "type": "integer"
            }
        },
        "properties" : {
            "fieldA" : {
                ...
            }
        }
    }
}

When using the samplesheetToList function I get warnings that these columns are unidentified:

WARN: Found the following unidentified headers in testfile.csv:
	- sample1
	- ...

I think that nf-core should either:

• treat these fields in the patternProperties as defined
• or add an option to disable the warning for unidentified headers

Also, I think this issue is somewhat related to: https://github.com/nextflow-io/nf-schema/issues/126

Start with the samplesheetToList function and trace how it identifies headers against the JSON schema. Check how patternProperties is handled for item objects and compare that with the warning in the example. Done means matching dynamic sample columns are treated as defined, or the requested warning-suppression option is supported with tests for the provided schema.