Remove License on DCAT dataset level

[hcvdwerf]

• The license field is not part of the main DCAT vocabulary at the dataset level.
• DCAT-AP specifies the license field only at the distribution level for each resource within the dataset.

Therefore, your proposal is to:

• Remove the license field from the dataset level in CKAN's DCAT schema.
• Retain the license field only at the distribution level to comply with DCAT standards. Improve functionality. Just like it was on Dataset leven
  This approach aligns with DCAT-AP 3 documentation ( https://semiceu.github.io/DCAT-AP/releases/3.0.0/#Distribution)