Add project-level DORA lead time graphs

What does this MR do?

Adds project-level DORA 4 lead time graphs as described in #250329 (closed).

This is very similar to the deployment frequency graphs added in !50885 (merged).

Screenshots

When hovering over an area of the chart that has data:

When hovering over an area of the chart that does not have data:

GIF:

Steps 👣

1. !58442 (merged)
2. !58708 (merged)
3. !57872 (merged) (this MR)

Related to #250329 (closed)