Add an example page for cardscan

[awush-stripe]

Summary

Create a test page for the cardscan flow

Motivation

We have no way of testing the cardscan flow manually presently.

Testing

• Added tests
• Modified tests
• Manually verified

Changelog

• [ADDED] 4562 Add an example page for cardscan

[github-actions]

Diffuse output:

OLD: paymentsheet-example-release-master.apk (signature: none)
NEW: paymentsheet-example-release-pr.apk (signature: none)

          │          compressed          │         uncompressed         
          ├───────────┬───────────┬──────┼───────────┬───────────┬──────
 APK      │ old       │ new       │ diff │ old       │ new       │ diff 
──────────┼───────────┼───────────┼──────┼───────────┼───────────┼──────
      dex │  11.8 MiB │  11.8 MiB │  0 B │  40.1 MiB │  40.1 MiB │  0 B 
     arsc │   1.6 MiB │   1.6 MiB │  0 B │   1.6 MiB │   1.6 MiB │  0 B 
 manifest │   2.7 KiB │   2.7 KiB │  0 B │  11.1 KiB │  11.1 KiB │  0 B 
      res │ 697.1 KiB │ 697.1 KiB │  0 B │   1.1 MiB │   1.1 MiB │  0 B 
    asset │  77.8 KiB │  77.8 KiB │  0 B │ 109.3 KiB │ 109.3 KiB │  0 B 
    other │  78.3 KiB │  78.3 KiB │  0 B │   154 KiB │   154 KiB │  0 B 
──────────┼───────────┼───────────┼──────┼───────────┼───────────┼──────
    total │  14.2 MiB │  14.2 MiB │  0 B │  43.1 MiB │  43.1 MiB │  0 B 

         │          raw           │           unique            
         ├────────┬────────┬──────┼────────┬────────┬───────────
 DEX     │ old    │ new    │ diff │ old    │ new    │ diff      
─────────┼────────┼────────┼──────┼────────┼────────┼───────────
   files │      3 │      3 │    0 │        │        │           
 strings │ 189052 │ 189052 │    0 │ 170340 │ 170340 │ 0 (+0 -0) 
   types │  32886 │  32886 │    0 │  30879 │  30879 │ 0 (+0 -0) 
 classes │  28488 │  28488 │    0 │  28488 │  28488 │ 0 (+0 -0) 
 methods │ 165500 │ 165500 │    0 │ 160603 │ 160603 │ 0 (+0 -0) 
  fields │ 122103 │ 122103 │    0 │ 121430 │ 121430 │ 0 (+0 -0) 

 ARSC    │ old  │ new  │ diff 
─────────┼──────┼──────┼──────
 configs │  297 │  297 │  0   
 entries │ 5389 │ 5389 │  0