[WIP] First attempt

[gabrielfior]

As described in this issue, the idea was to allow the user to specify a custom (valid) RPC endpoint. My approach involved the following parts: [ X ] Add components to handle user interaction (input, button) [X ] Handle network Options (all RPC endpoints - i.e. Shibuya, local node, etc) in a centralized way using the ApiContextProvider [ 1/2 X] Make the NetworkAndUser dropdown identify the custom node and accept it.

What is missing:

• The Dropdown does not "accept" the new value of local node, i.e. it still displays the initially specied local RPC node (RPC.local). I suspect a re-rendering of the component is necessary since networkOptions was changed (useEffect?).
• House-keeping (move networkOptions from ContextProvider to a separate class)
• Linting
• Writing Cypress tests
• Making sure tests pass (Cypress)

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[cla-bot-2021[bot]]

User @gabrielfior, please sign the CLA here.

[gabrielfior]

Regarding code review, no major points to add. However, I would imagine the user might want to specify multiple local nodes (occurs with me when using Hardhat for different forks), so it might be worth considering not updating the Local Node network definition every time and istead allowing for multiple configs.

[gabrielfior]

@statictype