Move stack trace formatting out of Span class

[tidal]

The method formatStackTrace should be moved from Span into a dedicated Util/Formatter class in the SDK\Common namespace since formatting stack traces is not the responsibility of a Span.

• Move logic in formatStackTrace from Span into a dedicated Util/Formatter class
• Add Backward compatibility by calling the new method from Span::formatStackTrace and tigger deprecation notice with Compatibility\Util::triggerMethodDeprecationNotice

[amber0612]

@tidal Please assign this issue to me. Thanks!

[amber0612]

Inorder to test, i need to know how we can re-produce the scenario which uses formatStackTrace function as I cannot find code which is currently using this function

[brettmc]

Span::recordException() calls the static method formatStackTrace: https://github.com/open-telemetry/opentelemetry-php/blob/main/src/SDK/Trace/Span.php#L295
Usually it would be invoked by something like

try {
  //something that might throw
} catch (\Throwable $t) {
  $span->recordException($t);
}