[NAVREDESIGN] Send screen

### **Description**

Update design of `Send` screen.

### **Technical Details**

- Convert screen to new design
- Update nav bar to include network + account switcher
- Screen should reflect switcher updates

### **Acceptance Criteria**

- TBD

### **References**

- Figma - https://www.figma.com/file/qcwJHEEw5qyNru5mbFf6Oq/Nav-Redesign-Breakdown?node-id=114%3A2008
- ETA - 5 days

Start with the Send screen in the mobile app and compare it with the linked Figma Nav Redesign breakdown. Update the screen to the new design, add the network and account switcher to the navigation bar, and ensure the screen reflects switcher changes; acceptance criteria are currently TBD.

Written by the indexing model from the issue text.