Directly implement ComputeAggregation

[fraillt]

Prerequisite for #2328

Currently part of aggregate measuring and collecting logic is scattered in several places:

• in AggregateBuilder
  • attribute set filtering is applied during measurement
  • collection method is selected for specified temporality
• in specific aggregate e.g. Sum
  • actual measurement is calculations are performed
  • actual collection happens, depending on which method was called in AggregateBuilder.

Instead we should implement all logic in one place (aggregate implementation e.g. Sum), and AggregateBuilder would be responsible only for initializing it.
This is especially important for #2328, because we want to be able to select specific implementation (depending on temporality) at compile time. The goal is to be able to initialize/build aggregation like this:

/// Builds a sum aggregate function input and output.
pub(crate) fn sum(&self, monotonic: bool) -> Arc<dyn Aggregate> {
  match self.temporality {
    Temporality::Delta => Arc::new(Sum::new(DeltaCollector::new(), monotinic)),
    _ => Arc::new(Sum::new(CumulativeCollector::new(), monotinic)),
  }
}

As a side effect this approach will also has less indirection which simplifies code, and might improve performance.

Changes

• Temporality is now passed in to aggregation during creation
• aggregations directly implements ComputeAggregation

Merge requirement checklist

• CONTRIBUTING guidelines followed
• Unit tests added/updated (if applicable)
• Appropriate CHANGELOG.md files updated for non-trivial, user-facing changes
• Changes in public API reviewed (if applicable)

[cijothomas]

Oops just merged the startTime PR! Could you resolve conflicts

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 76.8%. Comparing base (551760b) to head (5afd526).
Report is 1 commits behind head on main.

Additional details and impacted files

@@          Coverage Diff          @@
##            main   #2425   +/-   ##
=====================================
  Coverage   76.8%   76.8%           
=====================================
  Files        122     122           
  Lines      21806   21823   +17     
=====================================
+ Hits       16758   16772   +14     
- Misses      5048    5051    +3     

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[cijothomas]

nit: is this intentional?

[cijothomas]

Good move!