fix: flashing to continue on navigation changes

[barrenechea]

Refactored the flashing logic for both Firmware Upgrade and Flash Node tabs into a global provider & context, allowing it to continue no matter the tab the user is currently at.
The new context handles toasts and the reboot dialog (after Firmware Upgrade finishes), allowing it to report the status anywhere.

Also, here are some edge cases I've covered:

• Navigation links for either Flash Node or Firmware Upgrade will now pulse accordingly if a flashing procedure is ongoing to give the user a clue something is going on there.
• The UI will now allow only one Flash procedure at a time, disallowing a behavior where the user could have been running a Flash Node procedure and then attempting to do a Firmware Upgrade simultaneously.

The bundle size is at 1254 KB. Bumped patch version to 3.1.2.

Fixes #10

Caveat: Because React unmounts all unused components on navigation changes, I cannot keep the form states across tab changes. The tab will still report the progress for an ongoing flashing procedure, but the file and SHA-256 fields will be lost if the tab changes. If I store the form state in this new context, that would load the file into RAM... It does not sound like a good idea 😄

[barrenechea]

@svenrademakers, I've already tested it on my end, but it would be great if you could give this branch a spin to validate the fix! 🙏🏻

[svenrademakers]

issue solved! thanks for the quick fix! much appreciated!