fix: respect system precision in leave application dashboard and reports

[ruchamahabal]

Leave Application dashboard not respecting system precision:

Before:

After:

Leave Balance reports not respecting system precision:

Before:

After:

[codecov-commenter]

Codecov Report

Merging #300 (0191844) into develop (4024655) will decrease coverage by 0.06%.
The diff coverage is 100.00%.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop     #300      +/-   ##
===========================================
- Coverage    70.91%   70.85%   -0.06%     
===========================================
  Files          181      181              
  Lines         9158     9161       +3     
===========================================
- Hits          6494     6491       -3     
- Misses        2664     2670       +6     

Impacted Files	Coverage Δ
.../hr/doctype/leave_application/leave_application.py	79.24% <100.00%> (+0.04%)	⬆️
...t/employee_leave_balance/employee_leave_balance.py	94.59% <100.00%> (+0.09%)	⬆️
hrms/hr/doctype/shift_type/shift_type.py	87.50% <0.00%> (-4.55%)	⬇️
...ms/hr/doctype/shift_assignment/shift_assignment.py	90.77% <0.00%> (-0.49%)	⬇️
hrms/payroll/doctype/salary_slip/salary_slip.py	87.42% <0.00%> (-0.12%)	⬇️