Improvements to Custom RPC form

[bdresser]

Relates to general work to improve the Settings menu (#5790) but may be tackled separately / afterwards.

The custom RPC form is an important developer feature and we should give it its due!

Basic Functionality

We can add a top-level "Networks" category on the Settings designs outlined above. The category takes you to a page that lets you

• see a list of all your networks
• add a new custom network
• tap in to an existing network to view and/or edit

for each network, users should be able to set

• RPC URL (required)
• nickname
• chain ID
• symbol (ETH, ETC, ...)
• block explorer
• color picker (nice-to-have)

Other in-scope updates

Block explorers

• editable on any network (Allow custom block explorer #6083)
• accepts URLs in the format * https://${hostname}/tx/${transaction_id} or * https://${hostname}/address/${address}
• rinkeby should default to rinkeby.etherscan.io; ropsten to ropsten.etherscan.io (Custom Network pointing at Rinkeby Etherscan. #6127, Hide links to etherscan when no block explorer is specified for a custom network #5631)

Updates to universal network dropdown

• A fresh install of the extension should show Mainnet, Ropsten, Rinkeby, and "Manage Networks..." which will take the user to this page in settings
• Network names in the top bar should end in ellipses so they don't clip the account image, as described in Custom RPC makes account switcher unavailable #6094
• Behavior that persists saved networks and allows removing with the x should remain unchanged

Questions

• We may allow the option to edit default networks (Mainnet, Ropsten, etc). If we do, probably wise to include aan additional warning / double confirmation and a "return to default settings" button for those networks.
• Would be nice to include a "duplicate network" button somewhere on the index screen
• Would be nice to allow removing custom networks from the index screen
• Should we move the "show/hide fiat conversion on testnets" (Show/Hide Fiat on Testnets based on User Preference #6153) to a per-network setting? (i.e. "Show / hide fiat conversion on this network as a checkbox on each network form)

Addresses #5605, #5631, #5381, #6083, #6094

Working Mural is here

[bdresser]

with these updates to block explorer, we should consider changing instances of "view on Etherscan" to
"view on block explorer"

[danjm]

@bdresser Where are the finalized designs for this?

Never mind, found them :)