Add Codacy for code style check

[e-pettersson-ericsson]

Description

Align with Eiffel Intelligence back-end and add Codacy to check for code style violations in pull requests, and view test coverage.

There is an issue in the community repository about using one tool for code style checks in Eiffel community repositories.

Motivation

Easy to spot violations on code standards in new pull requests. The code coverage reports can give us statistics on in which areas we might need to improve our tests of the component.

Exemplification

See previous implementation (and tutorial) done in Eiffel Intelligence back-end

Benefits

Easier reviewing process without wasting time on minor mistakes which could be easily detected automatically.

Possible Drawbacks