Make named defintitions and their aliases consistent with - and remove _

Migrated issue

Reported by: jonathan1055

Related to !50 (merged) !49 (merged)

Problem/Motivation

The includes/include.drupalci.main.yml file defines some snippets for re-use elsewhere and has aliases for them. Most of the defined names have - as word separators, but a few use _ instead. However, all of the alias ids use - even when the name has _ and this causes unnecssary hassle when debugging the gitlab errors such as This GitLab CI configuration is invalid: !reference [".setup-webserver"] could not be found. In this case the alias is 'setup-webserver' but the name is 'setup_webserver'

Proposed resolution

Use - consistently in all names and aliases, so that reusing names via reference or aliases directly does not lead to unnecessary effort and problem solving.

This will also allow more easy reuse via references
- !reference [ .setup-webserver ]

The following are already consistent and do not need to be changed

.with-database: &with-database
.with-chrome: &with-chrome
.test-variables:
.show-environment-variables: &show-environment-variables

Remaining tasks

The following names need to be changed to match the alias

.simpletest_db: &simpletest-db
.setup_webserver: &setup-webserver

User interface changes

API changes

Data model changes