[TA] Expand test analytics to report on test analytics for "ALL Branches"

[rohan-at-sentry]

What product do you want to improve?
Test analytics from Codecov

Is your feature request related to a problem? Please describe.
Customers that experience flakes on CI runs likely don't want to search by individual branches to find aggregate counts of failures across ALL branches (main is also a branch).

Our current table data and stats rollups that are planned (see https://www.figma.com/design/TcppABudxnslgEmaXm0B9O/GH-2028?node-id=1-2&node-type=canvas&t=yLQARHqMTAuV6tZ1-0) are branch specific

Describe the solution you'd like
Showing totals for failures across all branches and average run times / failure rates across all branches would be cool - especially for tests that are known flaky

Write up - https://www.notion.so/sentry/Show-Test-Analytics-across-all-branches-1188b10e4b5d80d6880cc83a4f640251?pvs=4

[rohan-at-sentry]

Some other thoughts

1. Given that the tests dashboard on the main branch lists flake rate and failure rate on main - there isn't really an easy way to answer the question of how many flaky tests are impacting development in aggregate

2. We could change how flake rate or failure rate is calculated on main (since that's the only branch flake rate is shown). This would break consistency of the UI (we show all stats on a per branch basis) - that doesn't seem like a good thing to do

That's sort of why I'm leaning towards a "show all branches" type of roll-up. In that way we can have a view that shows stats for ALL branches in aggregate.

• It preserves our existing model
• We could have it selected by default

[Adal3n3]

We currently have "All branches" for commits, so I'm trying to learn about the scope of this request. @ajay-sentry @joseph-sentry do you know?

[joseph-sentry]

@Adal3n3 I think that's only for coverage at the moment, I don't think we have this for test analytics yet, and it may require some work both on the backend and frontend to get it working for test analytics

[rohan-at-sentry]

Folks asking for this in our feedback repo - codecov/feedback#304 (comment)