[Profiling] Differential views based on same data show different values

[rockdaboot]

Kibana version: 8.14-SNAPSHOT

Elasticsearch version: 8.14-SNAPSHOT

Describe the bug: The summary fields in the differential views for TopN Functions and Flamegraph should show the same values when calculated from the same data. But they don't.

Steps to reproduce:

1. In the Universal Profiling landing page, select a time range with data in the past (don't use last X minutes/hours/days)
2. Select the Functions view
3. Click on the "Differential TopN functions"
4. In a second browser tab, repeat step 1
5. In the second browser tab: Select on the Flamegraph view
6. In the second browser tab: Click on the "Differential Flamegraph"
7. Compare the values under "Annualized CO2 emission impact", "Annualized cost impact" and "Total number of samples" - they should be identical, but aren't.

Expected behavior: The summary fields in the differential views should show exactly the same data when based on the same data.

Screenshots (if relevant):

[elasticmachine]

Pinging @elastic/obs-ux-infra_services-team (Team:obs-ux-infra_services)

[rockdaboot]

Just seeing that there is also a little "glitch" in the first screenshot where 0 changes lead to a green arrow up and < 0.01%. It should just be zero without arrow, as seen in the second screenshot.

[rockdaboot]

~I verified the shown values are delivered by the ES profiling API.~ My mistake, used the data from Kibana server. cc: @danielmitterdorfer

[rockdaboot]

@cauemarcondes The following needs to be changed:

diff. topN functions - "Total number of samples"

• Use selfCPU from the Kibana server response, or even better: self_count from the ES response and avoid renaming fields on the Kibana server side. There is no need or use for total_count, TotalCount or totalCPU (IMO these fields can be dropped).

diff. topN functions - "Annualized CO2 / costs"

• There is a rounding error, that's why the values divert from what is shown in diff. Flamegraph. Please do not sum up any values and use self_annual_co2_tons and self_annual_cost_usd from the ES response.