Combine Cy and EventEmitter type before declaring global variables

[bahmutov]

Cypress v6.4.0

This is related to the issue #14991 where our types are less than optimal

I have described how to get rid of the global Cypress objects like cy, Cypress, assertion methods, and Mocha's functions in the blog post https://glebbahmutov.com/blog/local-cypress/ While looking at the types I have noticed a few weird things:

• the top-level type is a union of cypress and EventEmitter - which is confusing to the user I believe. This is done in https://github.com/cypress-io/cypress/blob/develop/cli/types/cypress-global-vars.d.ts

We can merge the type in our code and have the cy be just of type cy, same for the top-level Cypress type

Unfortunately, a simple solution like interface cy extends Chainable<undefined>, EventEmitter {} is blocked by an open MS issue microsoft/TypeScript#16936

[cypress-app-bot]

This issue has not had any activity in 180 days. Cypress evolves quickly and the reported behavior should be tested on the latest version of Cypress to verify the behavior is still occurring. It will be closed in 14 days if no updates are provided.