[native] Add URI scheme to debug Info.plist

Summary:
Resolves ENG-2730

Added the comm:// URI cheme to Info.debug.plist.
Didn't patch Expo, the --scheme flag is sufficient for now.

Test Plan:

• For physical device:
  1. Build app (in Xcode or yarn expo run:ios -d --no-bundler - see D6309) 2.

cd native
yarn dev --scheme comm

Note that the URL has changed to a deep link! see image below

3. Scan the QR code with the camera app. The Comm app should launch automatically, without the Expo launcher screen

• For simulator:
  1. Build app - same as above, just select simulator
  2. Same as above
  3. In the Metro console, press the i key on the keyboard (or shift+i for device select screen). The Comm app should launch automatically, without the Expo launcher screen

It is also possible to check if Expo's scheme utility uri-scheme detects the scheme correctly:

$ npx uri-scheme list --info-path ./ios/Comm/Info.debug.plist
› iOS: Schemes for config: ./ios/Comm/Info.debug.plist
› comm://

Reviewers: ashoat, atul

Reviewed By: ashoat, atul

Subscribers: tomek

Differential Revision: https://phab.comm.dev/D6319