update opentelemetry to 0.19.0

[garypen]

The update requires a change to the implementation and test update as follows:

• In otel 0.18.0, processor factories had a with_memory(bool) method which we were using when building our prometheus exporter. AFAICT, this used to be a mechanism for controlling how metrics handled stale gauges. In 0.19.0, this method was removed and now gauges are all assumed to be as though they were created with false. We had been providing true on our call. I'm not 100% certain of the impact of this change, but it appears that we can ignore it. We may need to consider it more carefully if problems arise.
• There are now two standard OTEL attributes: otel_scope_name="apollo/router",otel_scope_version="" added to output and a number of tests had to be updated to accommodate that change.
• One of our tests appeared to be searching for apollo_router_cache_hit_count (and this was working) when it should have been searching for apollo_router_cache_hit_count_total (likewise for miss). I've updated the test and think this is the correct thing to do. It looks like a bug was fixed in otel and this change matches the fix.

The upgrade fixes many of the outstanding issues related to opentelemetry and various APM vendors:

Fixes: #2878
Fixes: #2066
Fixes: #2959
Fixes: #2225
Fixes: #1520

Checklist

Complete the checklist (and note appropriate exceptions) before a final PR is raised.

• Changes are compatible[^1]
• Documentation[^2] completed
• Performance impact assessed and acceptable
• Tests added and passing[^3]
  • Unit Tests
  • Integration Tests
  • Manual Tests

Exceptions

Note any exceptions here

Notes

[^1]. It may be appropriate to bring upcoming changes to the attention of other (impacted) groups. Please endeavour to do this before seeking PR approval. The mechanism for doing this will vary considerably, so use your judgement as to how and when to do this.
[^2]. Configuration is an important part of many changes. Where applicable please try to document configuration examples.
[^3]. Tick whichever testing boxes are applicable. If you are adding Manual Tests:
- please document the manual testing (extensively) in the Exceptions.
- please raise a separate issue to automate the test and label it (or ask for it to be labeled) as manual test

[router-perf]

CI performance tests

• const - Basic stress test that runs with a constant number of users
• no-graphos - Basic stress test, no GraphOS.
• step - Basic stress test that steps up the number of users over time
• reload - Reload test over a long period of time at a constant rate of users
• xlarge-request - Stress test with 10 MB request payload
• large-request - Stress test with a 1 MB request payload
• xxlarge-request - Stress test with 100 MB request payload

[tmc]

would love to see this go in