Add test coverage

[ackzell]

We want coverage for this repo, namely:

• Unit tests for the components and their logic (Jest)
• E2E testing for the whole app (Cypress.io)
• Visual tests that indicate the different states of the app (Storybook)
• Manual tests

Any type of test that makes sense for this app.

[diego-zco]

Observation 1:
Env: Chrome/Android
Description: The user can record and remove multiple messages before actually saving one. It seems if the user removes nine messages, and then attempts to save a tenth one, nothing is recorded (empty message with reproduction button but no content)

[diego-zco]

Obersvation 2:
Env: Chrome/Desktop
Description: When trying to record and remove multiple messages, the 23rd is saved and from that one, any new message is saved without allowing to remove them. The 23rd message seems to be complete, but the rest of messages are "empty instances."