feat(core)!: remove TracesSamplerValues from exports

[pichlermarc]

Which problem is this PR solving?

TracesSamplerValues was part of the public API of @opentelemetry/core, even though we never consume it anywhere other than in @opentelemetry/sdk-trace-base. This PR removes the export from core and moves it into the trace package to cut down on API surface. Also makes the enum a const enum instead for size reasons and since we only use it internally.

Refs #5172

Type of change

Please delete options that are not relevant.

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

How Has This Been Tested?

• Existing tests

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 94.64%. Comparing base (c513965) to head (1614c10).
Report is 3 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5406      +/-   ##
==========================================
- Coverage   94.64%   94.64%   -0.01%     
==========================================
  Files         318      317       -1     
  Lines        8033     8025       -8     
  Branches     1688     1687       -1     
==========================================
- Hits         7603     7595       -8     
  Misses        430      430              

Files with missing lines	Coverage Δ
...ckages/opentelemetry-core/src/utils/environment.ts	96.82% <ø> (-0.05%)	⬇️
...ackages/opentelemetry-sdk-trace-base/src/config.ts	88.37% <100.00%> (ø)