feat(ios): Add "Image" Option to the Mobile App Share Button

Copy of #12485 for iOS app from @dyacob

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

Texting in a script that is not yet supported on iOS or Android devices requires many extra steps. This scenario happens when the mobile OSes are slow to update fonts for a Unicode update (Ethiopic Extended-B for example), or in cases for neography that is going through a lengthy Unicode adoption process.

### Describe the solution you'd like

The "Share" button at the top of the mobile app would show a drop-down menu when long-pressed, the menu items would be:

* `Text`
* `Image`

The `Text` would be the default action (also for a short-press) and work as per the present behavior. The `Image` option would create an image of the yellow area of the editor, and this image is then what gets shared with another app.

The image of the edit area would include the entire area, including text that may have scrolled off of the screen.

As an alternative to a menu of options, a 2nd share button could be added with a small image icon in the corner.

### Describe alternatives you've considered

Making a screenshot of my entire phone screen, cropping to just the editor text, saving, and sending the file. This alternative has too many steps which makes it unfriendly. It may also require the user to repeat the steps multiple times when text has scrolled offscreen.

### Related issues

_No response_

### Keyman apps

- [ ] Keyman for Android
- [X] Keyman for iPhone and iPad
- [ ] Keyman for Linux
- [ ] Keyman for macOS
- [ ] Keyman for Windows
- [ ] Keyman Developer
- [ ] KeymanWeb
- [ ] Other - give details at bottom of form

### Keyman version

Any

### Operating system

iOS, iPadOS

### Device

Any

### Target application

Messenger Apps, Keyman mobile editor

### Browser

N/A

### Keyboard name

Any

### Keyboard version

Any

### Language name

Any

### Additional context

_No response_