* Export new COMMAND_FIREFOX_VIEW from FxAccountsCommon for the command string
* Call a new openFirefoxView method when the feature pref is enabled
* Pass along an entryPoint param - this is speculative: we don't handle this currently but its what the COMMAND_PAIR_PREFERENCES does and seems reasonable
* New test to confirm that this openFirefoxView method will indeed get called when the right web channel message is received. Note, this doesnt confirm that FirefoxViewHandler.openTab actually results in fx-view being opened, but it will at least fail if that moves or gets renamed in the future
Differential Revision: https://phabricator.services.mozilla.com/D150527
aff792070a