Implement Install Extension notification for IPFS properties

[whizzzkid]

To encourage more users to start using the ipfs-companion extension, we can build a nudge notification for users to install the ipfs-companion browser extension.

This notification will show up on ipfs properties and display a call-to-action for the user to install the companion extension.

[juliaxbow]

We don't have a standard notification system built into desktop/webUI AFAIK (other than a module for data collection, but I don't think a module makes sense in this context). I also hesitate in having a pop up window unless it were triggered with a very specific action in which the user would benefit from using companion. As I'm not sure we can do that based on what user data we have access to, I'd suggest a simple automatic notification:

Option 1 I think we could seamlessly add a notification button to the top bar and a notification dropdown to appear on click

Pros:

• familiar notification system for users
• could include future notifications here as well (e.g. cookie notice)

Cons:

• it's not so much a notification as it is a product/feature recommendation.
• Slightly crowds the top right corner of webui/desktop app. Though I do think we should reconsider those buttons anyways

Option 2 Add a notification alert to the settings button.

Pros:

• Doesn't add a new button, only a notification alert.
• Settings seems like the best place within the existing ui to keep product recommendations and/or links to documentation Cons:
• It requires the user to navigate to a new page and away from their current work stream
• An alert on "settings" may make the user think that a core function of desktop or webui is not working or requires attention

Other considerations: Since we don't necessarily know what browser desktop users will be using, we may want to just link to companion documentation, which has clear instructions for installing the browser extension from different add-on stores. I'll draft an alert then update this github issue