Move data validation functions into shared module

[joneubank]

Validation functionality provided by the Lectern Client is moved into its own module. This module is added at the path libraries/validation and will be published as @overture-stack/lectern-validation.

This module exports all logic for validating data record value types and all restrictions as defined in the current Lectern Dictionary. The validation pipelines and processing functions remain in the client for now as these will likely require refactoring along with the conditional restriction work. No sense to refactor them to support generalization when we will only tear them apart in a short time.

Changes

• Creation of Validation module
• Moving all validation functions out of client and into shared validation module
  • data type validations
  • restriction validations (dictionary and schema level)
• Client processing code relies on validation module