feat: make context.active() the default value for certain context functions

[naseemkullah]

This is actually discussed there #27 for another reason though

functions where I'm adding a default context as context.active(), based on searching the otel-js repo for their invocations:

• getSpan()
• setSpan()
• suppressInstrumentation()

💥 breaks setSpan() as it reverses the order of params.

This PR also serves a discussion. Is this a better default or not?

Pros: it will reduce boilerplate code, helper functions aside/when working with lowest level api

Cons: ?

[codecov]

Codecov Report

Merging #30 (9ae85c2) into main (504041a) will increase coverage by 0.01%.
The diff coverage is 100.00%.

❗ Current head 9ae85c2 differs from pull request most recent head db90004. Consider uploading reports for the commit db90004 to get more accurate results

@@            Coverage Diff             @@
##             main      #30      +/-   ##
==========================================
+ Coverage   94.64%   94.65%   +0.01%     
==========================================
  Files          39       39              
  Lines         504      505       +1     
  Branches       81       84       +3     
==========================================
+ Hits          477      478       +1     
  Misses         27       27              

Impacted Files	Coverage Δ
src/context/context.ts	92.68% <100.00%> (+0.18%)	⬆️

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[dyladan]

This PR also serves a discussion. Is this a better default or not?

In the past we have been moving in the opposite direction. For low-level API primitives we have typically considered it to be better to have more explicit parameters.

/cc @Flarna because I know you've expressed opinions in the past that you believe we already have too many cases where context has a default value of active()

[Flarna]

I removed the context.active() as default for propagation.extract() and propagation.inject() in open-telemetry/opentelemetry-js#1734
As mentioned there at least in extract using context.active() (which may contain a span reference) is most likely what noone wants.

The helper functions here are somewhat different as they are used more frequently at places where context.active() is what someone wants - similare as in tracer.startSpan().

I'm not a big fan of using references to globals in default arguments as it makes it terrible hard to consistent use non global ContexManger, TracerProvider,...

I'm also not sure if a breaking change is still acceptable in current stage (see #15 (comment)).

[naseemkullah]

Thanks for the detailed explanation! Closing