Check bundle hash to avoid duplicate work

[sondreb]

This commit does not appear to work: 0a7fd1d

The app is suppose to only run protocol registration each time the hash changes.

[sondreb]

There is already some logic for getting the hash in the update.service.ts, look into using this to store the previous hash and validate on load in app.component.ts.

Example from app log:

Current app version: d5b2e679930a574f058bf636c68b60400d662686
New app version ready for use: 04b428cc21fbe2c334ea743874b5e91385a60369