[APM] Meta: Service transaction metrics, rollups and `transaction.duration.summary` field everywhere

[sorenlouv]

To improve performance we aim to make the following changes:

• Use service transaction metrics instead of transaction metrics where possible
• Use transaction.duration.summary instead of transaction.duration.histogram where possible
• Use rollups everywhere

This work is captured in the following issues:

• https://github.com/elastic/kibana/issues/138527
• https://github.com/elastic/kibana/issues/146734
• https://github.com/elastic/kibana/issues/152693
• https://github.com/elastic/kibana/issues/146683
• https://github.com/elastic/kibana/issues/143848

Remaining work:

• Apply rollups everywhere
• Refactor source in roll-up response: https://github.com/elastic/kibana/pull/153162#discussion_r1143978003

[elasticmachine]

Pinging @elastic/apm-ui (Team:APM)