Add CI_COMPONENT_FQDN variable and usage instructions
What does this MR do and why?
Currently, the FQDN is written hard-coded into components and pipeline configs. This will cause more changes needed when self-hosted instances mirror a component from gitlab.com and try to use it.
As a result, we are introducing the CI_COMPONENT_FQDN
variable.
It will be the suggested way when creating a component and using it.
Related to #434260 (closed) and #415638.
Next step; Write steps to use gitlab.com CI catalog compon... (!146020 - merged).
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Edited by Furkan Ayhan