Fire device/folder approval notifications on app start (fixes #467)

[Catfriend1]

Purpose:

• "Make use of persistent devicePending and folderPending config nodes" (fixes Make use of persistent devicePending and folderPending config nodes #467)
• Fire device/folder approval notifications on app start

Caused by change in upstream:
syncthing/PR 5084 - syncthing/syncthing#5084

Testing with AVD 9.x at commit #0114cae - verified working.

[Catfriend1]

 I/SyncthingNativeCode: [YLW7H] INFO: Connection from 7LTUV3P-Y37HQXK-UUM7S5Q-2NDQT3B-SA4WAT4-T5ODX3V-XRXAF7Z-MXM7GAA at 89.221.214.63:22067 (relay-server) rejected: unknown device
2019-08-31 15:20:37.752 10057-10120/ D/Volley: [461] BasicNetwork.logSlowRequests: HTTP response for request=<[ ] https://127.0.0.1:8384/rest/events?since=19&limit=0 0x59c3b57d NORMAL 612> [lifetime=38090], [size=8603], [rc=200], [retryCount=3]
2019-08-31 15:20:37.760 10057-10057/ V/EventProcessor: Forwarding ConfigSaved event to RestApi to get the updated config.
2019-08-31 15:20:37.760 10057-10057/ V/ApiRequest: Performing request to https://127.0.0.1:8384/rest/system/config
2019-08-31 15:20:37.760 10057-10057/ D/EventProcessor: Unknown device 'TEST' (7LTUV3P-Y37HQXK-UUM7S5Q-2NDQT3B-SA4WAT4-T5ODX3V-XRXAF7Z-MXM7GAA) wants to connect
2019-08-31 15:20:37.783 10057-10057/ D/RestApi: onReloadConfigComplete: Successfully parsed configuration.
2019-08-31 15:20:37.783 10057-10057/ V/RestApi: mConfig.pendingDevices = [{"address":"89.221.214.63:22067","deviceID":"7LTUV3P-Y37HQXK-UUM7S5Q-2NDQT3B-SA4WAT4-T5ODX3V-XRXAF7Z-MXM7GAA","name":"TEST","time":"2019-08-31T13:20:38Z"}]
2019-08-31 15:20:37.783 10057-10057/ V/RestApi: mConfig.remoteIgnoredDevices = []
2019-08-31 15:20:37.783 10057-10057/ V/RestApi: pendingDevice.deviceID = 7LTUV3P-Y37HQXK-UUM7S5Q-2NDQT3B-SA4WAT4-T5ODX3V-XRXAF7Z-MXM7GAA('TEST')

[Catfriend1]

Under the device offering a folder:
<pendingFolder time="2019-11-10T15:32:41+01:00" id="9MeeC-6yyAY" label="lp_test"></pendingFolder>

[Catfriend1]

Ignoring the folder gives below the offering device node:
<ignoredFolder time="2019-11-10T14:33:46.777Z" id="9MeeC-6yyAY" label="lp_test"></ignoredFolder>

[Catfriend1]

@ Review / Complete.
lgtm.