feat: allow Leave Encashment amount to be editable

[jigneshpshah]

Is your feature request related to a problem? Please describe.

Problem : A Salary Structure is assigned to multiple employees ( that is core purpose of salary structure) having different base salary , so leave encashment cannot be common for all employees having a common salary structure.

Describe the solution you'd like

Every organisation would be having a different way of calculating the leave encashment, till the time formula based salary component option/feature is made available , allow user to edit the Encashment Amount by calculating it manually.

Describe the alternatives you've considered

set field level permission & give edit rights for the field Encashment Amount to HR Manager .

Additional context

It is very important just to allow to edit Leave Encashment Amount field, else the Leave Encashment feature is worthless as of now due to this limitation