Add Test for Split Percentages Boundaries

[Baskarayelu]

Description:

The remittance split contract accepts any quadruple of non-negative percentages that sum to 100. Edge cases include allocating 100% to a single category (e.g. 100/0/0/0 or 0/100/0/0) or equal splits (25/25/25/25). If validation or storage were to reject valid edge cases, or if get_split returned different values than those passed to initialize_split or update_split, downstream logic (e.g. calculate_split) would produce wrong amounts. This issue adds tests that call initialize_split (or update_split after init) with these boundary inputs and assert get_split returns the same four values and calculate_split uses them correctly.

Requirements

Test cases: After initializing the split (as owner), test at least: (1) 100, 0, 0, 0 – assert get_split returns [100, 0, 0, 0] and calculate_split(env, 1000) returns [1000, 0, 0, 0]; (2) 0, 100, 0, 0 – same idea; (3) 25, 25, 25, 25 – get_split returns [25, 25, 25, 25] and amounts are quartered. Ensure the contract does not reject valid zero-percent categories.

Acceptance Criteria

• Tests for 100/0/0/0, 0/100/0/0, and 25/25/25/25 (or similar) with get_split and optionally calculate_split assertions.
• Tests are in remittance_split test suite and run in CI.