Add E2E testing tool

[brunomenezes]

📄 Context

The idea is to have automated regression testing when new changes are deployed. Unit tests are good, but they only deliver a certain level of guarantee, which is evident when mocking starts (No evil here, just part of the usual flow). Also, E2E tools have the advantage that they are often not attached to any specific underlying tech, behaving as a real user who also does not care what the App is running on. 😏

🔍 Tracking

• [x] #162
• [x] #166
• [x] #168
• [x] #170
• [x] #183
• [x] #189
• [x] #190
• [x] #188
• [ ] #192
• [x] #193

[brunomenezes]

That is the gist. I will be converting each of the task list items into an issue later, but I think that is the gist of it. Maybe the Send Transaction one will need to be broken into more pieces since the first may be the hardest one because it needs to interact with a wallet to be able to do any action (It will become the blueprint for the rest though)

cc: @nevendyulgerov , @dandheedge