Add New Case | Case Details | Drug Related Charge | Add Amount Range of Drug Possessed

### Background on the problem the feature will solve/improved user experience
As a Public Defender/Staff Member, I want to add the amount range of drug possessed when adding a new drug related case. Currently, the dropdown for amount range of drug possessed shows a list of races when clicked.

### Describe the solution you'd like
Instead of the current dropdown, there should be a text box for entering numerical value in terms of pounds of drugs.

### Tasks

- [ ] Replace the current dropdown with a text box for numerical values
- [ ] Add indication somewhere (Maybe the hint in the text box) that the unit of measurement of drugs is in pounds
- [ ] Add tests

### Acceptance Criteria
The user should be presented with a text box that receives numerical input for the drug amount.