Add Cypress framework

[chinchang]

We should start adding e2e tests with Cypress.

[chinchang]

@arnabsen1729 List of tests we can have:

• type in some html, hit save. there should be something in the localstorage with "untitled.." in name
• change the creation title, it should auto save in localstorage. Also a toast should show up saying it was saved.
• Clicking "OPEN" should open the saved items pane.
• Saved items should show up in the saved items pane
• "Add Library" should open the add library modal. Selecting any library from dropdown should change the URL in the textarea fields. Selecting another library should add the URL in a newline in the textarea fields.

[arnabsen1729]

• [x] type in some html, hit save. there should be something in the localstorage with "untitled.." in name
• [x] change the creation title, it should auto save in localstorage. Also a toast should show up saying it was saved.
• [x] Clicking "OPEN" should open the saved items pane.
• [x] Saved items should show up in the saved items pane
• [x] "Add Library" should open the add library modal. Selecting any library from dropdown should change the URL in the textarea fields. Selecting another library should add the URL in a newline in the textarea fields.