dag: Add noParamOverride optional field to the DAG level fields

[yohamta]

Add a new optional field to prevent users from overriding default parameters for a given DAG.

This feature involves the following tasks:

• internal/dag: Add a new builder function for the noParamOverride field.
  Example configuration:

  noParamOverride: true

• cmd and agent: Modify to throw an error if parameters are provided for a DAG with noParamOverride set to true.
• ui: Update the Start dialog to hide input fields when noParamOverride is specified.
• doc: Update the schema documentation to include details about the new field.