Add result-based assertion helpers and complete he_assert todo tests

[AlexKalll]

This PR adds the missing result-based assertion helpers (assertEqualToResult & assertAlphaEqualToResult ) and activates the TODO tests that depend on them.

Updates

1. Added assertEqualToResult in lib_he.metta, which uses assertEqual.
2. Added assertAlphaEqualToResult in lib_he.metta, which uses assertAlphaEqual.
3. Replaced commented TODO lines with active tests in he_assert.metta.

Validation

• Ran: time sh run.sh he_assert.metta
• Result: all tests passed

[patham9]

Looks good, thank you!