Feat: Completed Implementation of `role_store` contract.

[ametel01]

Summary

Implemented role_store and added corresponding tests.

Labels

• [x] Feature

Issue Resolved

Resolves: #432

New Behavior

The new implementation mimics the behavior of the Solidity version but avoids using arrays in storage. Instead, role_members_count and roles_count track the total number of writes rather than the actual instance count. This is because deleting a <key, value> pair sets the value to zero() rather than removing it. To manage storage efficiently, the algorithm checks existing keys from 0 to the current storage count during insertion. If a zero() value is found, that key is reused; otherwise, a new key-value pair is created and the key count is incremented.

Breaking Changes

None.

Additional Info

N/A

[ametel01]

Nice, could you just rename some test to follow our test naming rules

Like in the first test -> given_normal_conditions_when_revoke_role_then_works

renamed tests

[zarboq]

Sorry I wasn't clear but the test you renamed was the one with good naming :)

Rename other tests following the same pattern (given_...)

[ametel01]

Sorry I wasn't clear but the test you renamed was the one with good naming :)

Rename other tests following the same pattern (given_...)

done