Merge Percona Everest GitHub repositories, from three to one

Hi,

The Percona Everest project has recently moved to Beta status. Not only the product itself is being updated, but also the development processes.

When the development of the first versions started, the code of different components was published in different repositories.

It seemed logical and had its benefits. Each component could be built, modified, and documented separately.
However, in the process, this made it more difficult to set up CI/CD processes and support the infrastructure.

The team concluded that it was easier to merge the three repositories into one, and the merge was finalized today.

Well, we developers have completed the technical part, reconfigured dev processes and now we are developing in a new repository.
We invite you to star.