feature(core) Stricter validation for atomic values

[jeromesimeon]

Signed-off-by: Jerome Simeon [email protected]

Issue #157

A stricter validation semantics for atomic types and values in CTO models.

Changes

• Atomic values in the JSON have to be strictly of the type declared in the model. E.g., true validates against Boolean but "true" does not. E.g., 3.14 validates against Double but does not validate against Integer or Long. E.g., "1" validates against String but 1 does not.
• Updates the tests accordingly

Flags

• This is a breaking change
• The PR is against a new release-0.83 branch