Implement improved flow of opening channels

[stackingsaunter]

Flow was tested and improved after usability test among 4 users, two rather beginners with low technical/node/channels knowledge and 2 with a bit more.

Figma and mobile design

Intermediary page

All users from usability test claimed they initiated channel opening through main "Open Channel" CTA. This page is what appears when user clicks it, and describes two types of channels

Payment methods page

When chosen to open a channel with only spending balance, user views a choice of payment methods that lead to 3 different flows. This also shows when user clicks "Top Up" on Node page

Open Channel with On-chain

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Open Channel with Lightning

This page also appears when users clicks "Increase" on Node page

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Open Channel with Card / Wire