refactor(Select, AssignToCompanyModalContent): enhance select placeholder and integrate company query

- Updated the Select component to disable the placeholder option for better user experience.
- Refactored AssignToCompanyModalContent to accept a companiesQuery prop, improving data handling.
- Adjusted the useCustomerListPresenter hook to include the company query, ensuring it is only enabled when the assign company modal is open.
- Enhanced the CustomersTable component to pass the company query to the modal content.

src/components/FormElements/select.tsx

@@ -115,7 +115,11 @@ export function Select<T extends FieldValues>({
             clearable && value && "pr-20",
           )}
         >
-          {placeholder && <option value="">{placeholder}</option>}
+          {placeholder && (
+            <option value="" disabled>
+              {placeholder}
+            </option>
+          )}
 
           {items.map((item) => (
             <option key={item.value} value={item.value}>