* Refactor TraceState
* Update tracecontext propagator to use new TraceState
* Add TraceStateFromKeyValues to oteltest
* Use oteltest to test TraceState
* Replace IsEmpty with Len for TraceState
* Replace ParseTraceState with ParseTraceStateString
* Clean up naming
* Add immutability test for TraceState
* Add changes to changelog
* Fixes
* Document argument type change in changelog
* Address feedback
Remove circularity of TestTraceStateLen.
* Add a tool to auto-generate replace directives
* Auto-generated changes from previous commit
* Create new modules required for trace release
* otel/metric
* otel/trace
* otel/oteltest
* otel/sdk/export/metric
* otel/sdk/metric
Relates to #1467
* Move metric-related public API out of otel/ pkg
Move GetMeterProvider, Meter and SetMeterProvider to new package
otel/metric/global in the otel/metric module.
This will allow otel/ module to be released as v1.0.
* Include PR references in CHANGELOG
Co-authored-by: Tyler Yahn <MrAlias@users.noreply.github.com>
* Check for root dir
Co-authored-by: Tyler Yahn <MrAlias@users.noreply.github.com>