chore(sdk-metrics): clean up exports

[pichlermarc]

Which problem is this PR solving?

@opentelemetry/sdk-metrics exports some classes and functions that are intended for internal use. In an effort to reduce the API surface before declaring metrics GA, this PR replaces the existing wildcard exports with explicit exports.

Related: #3158

Short description of the changes

Replaces the existing wildcard exports with explicit exports and removes export for:

• AccumulationRecord
• Aggregator
• AggregatorKind
• Accumulation
• CollectionResult
• createInstrumentDescriptor
• createInstrumentDescriptorWithView
• isDescriptorCompatibleWith
• TimeoutError

Type of change

• Breaking change (fix or feature that would cause existing functionality to not work as expected)

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

• existing tests

Checklist:

• Followed the style guidelines of this project
• Unit tests have been added
• Documentation has been updated

[codecov]

Codecov Report

Merging #3197 (291470c) into main (a5abee6) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main    #3197   +/-   ##
=======================================
  Coverage   93.21%   93.21%           
=======================================
  Files         196      196           
  Lines        6443     6443           
  Branches     1363     1363           
=======================================
  Hits         6006     6006           
  Misses        437      437           

Impacted Files	Coverage Δ
...opentelemetry-sdk-metrics/src/export/MetricData.ts	100.00% <ø> (ø)

[legendecas]

Thank you for working on this.

[MSNev]

👍 We should be explicit about what is exported.