[Json Schema] Increase coverage of constraints/validators

[Krever]

Lets make all of the below result in a validator and that we have tests for it

🔤 String Constraints

• minLength: Minimum number of characters
• maxLength: Maximum number of characters
• pattern: Regular expression the string must match

🔢 Number / Integer Constraints

• minimum: Minimum value (inclusive)
• maximum: Maximum value (inclusive)
• exclusiveMinimum: Must be strictly greater than this value
• exclusiveMaximum: Must be strictly less than this value
• multipleOf: Must be a multiple of the given number

Other

• const: Value must match exactly

📦 Array Constraints

• minItems: Minimum number of elements
• maxItems: Maximum number of elements
• uniqueItems: All elements must be unique

🧩 Object Constraints

• minProperties: Minimum number of properties
• maxProperties: Maximum number of properties