Bug 41608 - Tidy up the TorConnect API for broad error states that the
different UI components can share.

Rename the `hasBootstrapEverFailed` to `potentiallyBlocked` as a
specific failure state.

Add the `hasEverFailed` boolean property as a catch-all failure state.

Add an `enabled` boolean property, which just maps to whether we own the
tor process.

Bug 41608 - Tidy up the TorConnect API for broad error states that the
different UI components can share.

Just use the HasEverFailed state to determine whether to show "Try
Again" or to show breadcrumbs.

fixup! Bug 31286: Implementation of bridge, proxy, and firewall settings in about:preferences#connection

Bug 41608 - Tidy up the TorConnect API for broad error states that the
different UI components can share.

No longer import TorMonitorService, and just use TorConnect instead.

+ Use TorConnect.enabled to determine whether to show the settings.
+ Use TorConnect.hasEverFailed state rather than
  TorMonitorService.bootstrapErrorOccurred to determine whether to show
  "Try Again".
+ Use TorConnect.potentiallyBlocked to determine whether to show the
  location selector. E.g. we don't want to show this if we just failed
  an internet connection test.

Bug 41608 - Remove unused TorMonitorService.bootstrapErrorOccurred

Bug 41608 - Remove unused TorMonitorService.bootstrapErrorOccurred

Bug 41608 - Add the canBeginBootstrap and canBeginAutoBootstrap
properties  to determine whether it is possible to enter the
corresponding TorConnectState from the current state.

Add options to openTorConnect to begin bootstrapping or
auto-bootstrapping once opened.

fixup! Bug 31286: Implementation of bridge, proxy, and firewall settings in about:preferences#connection

Bug 41608 - Use TorConnect.canBeginBootstrap and
TorConnect.canBeginAutoBootstrap and use bootstrapping options in
openAboutTor.

Selecting a location in the preferences now also opens
"about:torconnect".

Bug 41608 - Remove the FatalError state since it is not defined in
TorConnect.