Add SpanExporterFactory support for zipkin exporter

[jack-berg]

Builds on #5751, #5687, #5399, #5757, #5758, #5763 by adding logic to interpret the sampler portion of configuration schema.

[codecov]

Codecov Report

Patch coverage: 92.85% and project coverage change: -0.02% ⚠️

Comparison is base (01503ef) 91.34% compared to head (c9aca7c) 91.32%.

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #5771      +/-   ##
============================================
- Coverage     91.34%   91.32%   -0.02%     
- Complexity     5335     5341       +6     
============================================
  Files           592      592              
  Lines         15811    15831      +20     
  Branches       1564     1567       +3     
============================================
+ Hits          14442    14458      +16     
- Misses          937      939       +2     
- Partials        432      434       +2     

Files Changed	Coverage Δ
...try/exporter/zipkin/ZipkinSpanExporterBuilder.java	94.11% <80.00%> (-3.61%)	⬇️
...ntelemetry/exporter/zipkin/ZipkinSpanExporter.java	93.47% <100.00%> (+0.29%)	⬆️
...sion/incubator/fileconfig/SpanExporterFactory.java	92.30% <100.00%> (-2.82%)	⬇️

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