Refactor naming of pipeline object hierarchy methods

What does this MR do?

Related to #254801 (closed)

With this, we will use self_and_ancestors for same-project pipelines and self_and_upstreams for all upstream/downstream pipelines including multi-project pipelines.

• First introduction of these methods: !41102 (merged)
• Then, adding other methods: !29710 (merged)

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