[PWA] WebAppManifest: screenshots and shortcuts support

[pizzi80]

• WebAppManifest Screenshots and Shortcuts
• "final" on inner classes effective final fields
• typo

I tried to follow the documentation standard (which is very informative btw 👍 )

[BalusC]

There are test failures

Error:  Failures: 
Error:    PWAResourceHandlerIT.verifyManifest:67 expected: <{"categories":[],"dir":"auto","display":"browser","icons":[{"sizes":"512x512","src":"\/PWAResourceHandlerIT\/jakarta.faces.resource\/icon.png.xhtml?v=1","type":"image\/png"}],"lang":"en","name":"PWAResourceHandlerIT","orientation":"any","prefer_related_applications":false,"related_applications":[],"start_url":"http:\/\/127.0.0.1:8080\/PWAResourceHandlerIT\/"}> but was: <{"categories":[],"dir":"auto","display":"browser","icons":[{"sizes":"512x512","src":"\/PWAResourceHandlerIT\/jakarta.faces.resource\/icon.png.xhtml?v=1","type":"image\/png"}],"lang":"en","name":"PWAResourceHandlerIT","orientation":"any","prefer_related_applications":false,"related_applications":[],"screenshots":[],"shortcuts":[],"start_url":"http:\/\/127.0.0.1:8080\/PWAResourceHandlerIT\/"}>
[INFO] 
Error:  Tests run: 143, Failures: 1, Errors: 0, Skipped: 2

[pizzi80]

should be fixed ...