[Feature request] OpenLineage query_plan and query_statistics should be in JSON format

[dolfinus]

I've executed very simple query with OpenLineage integration enabled:

use pg.public;
insert into cde(id,value) select id,value from abc;

And got OpenLineage events:
ol_query_start.json
ol_query_complete.json

Resulting events contain facets trino_metadata and trino_query_statistics, but there are few issues preventing them to be used:

• trino_metadata.query_plan is a text representation of plan. For automatic plan inspection it's better to include the same plan in JSON format, as another field in the same facet.
  

  trino/core/trino-spi/src/main/java/io/trino/spi/eventlistener/QueryMetadata.java

  Line 47 in c36815a

  private final Optional<String> jsonPlan;

• trino_query_statistics facet contain a lot of fields, all of them have string values, even if value is actually an integer or float number:
  

  trino/core/trino-spi/src/main/java/io/trino/spi/eventlistener/QueryStatistics.java

  Lines 50 to 65 in c36815a

  	private final long peakUserMemoryBytes;
  	private final long peakTaskUserMemory;
  	private final long peakTaskTotalMemory;
  	private final long physicalInputBytes;
  	private final long physicalInputRows;
  	private final long processedInputBytes;
  	private final long processedInputRows;
  	private final long internalNetworkBytes;
  	private final long internalNetworkRows;
  	private final long totalBytes;
  	private final long totalRows;
  	private final long outputBytes;
  	private final long outputRows;
  	private final long writtenBytes;
  	private final long writtenRows;
  	private final long spilledBytes;

{
    "processedInputRows": "2",
    "physicalInputRows": "2",
    "processedInputBytes": "22",
    "analysisTime": "0.039000000",
    "internalNetworkRows": "4",
    "completedSplits": "11",
    "spilledBytes": "0",
    "outputBlockedTime": "0.0",
    "peakTaskTotalMemory": "288",
    "physicalInputBytes": "0"
}

• Some fields in trino_query_statistics facet contains nested fields which are objects in Java QueryStatistics class, and instead of JSON they are returned as string representation of Java object:
  

  trino/core/trino-spi/src/main/java/io/trino/spi/eventlistener/QueryStatistics.java

  Lines 75 to 78 in c36815a

  	private final List<StageCpuDistribution> cpuTimeDistribution;
  	private final List<StageOutputBufferUtilization> outputBufferUtilization;
  	private final List<StageTaskStatistics> taskStatistics;
  	private final List<StageOutputBufferMetrics> outputBufferMetrics;

{
    "cpuTimeDistribution": "[{stageId=0, tasks=1, p25=15, p50=15, p75=15, p90=15, p95=15, p99=15, min=15, max=15, total=15, average=15.0}, {stageId=1, tasks=1, p25=6, p50=6, p75=6, p90=6, p95=6, p99=6, min=6, max=6, total=6, average=6.0}, {stageId=2, tasks=1, p25=3, p50=3, p75=3, p90=3, p95=3, p99=3, min=3, max=3, total=3, average=3.0}]",
    "stageGcStatistics": "[{stageId=0, tasks=1, fullGcTasks=0, minFullGcSec=0, maxFullGcSec=0, totalFullGcSec=0, averageFullGcSec=0}, {stageId=1, tasks=1, fullGcTasks=0, minFullGcSec=0, maxFullGcSec=0, totalFullGcSec=0, averageFullGcSec=0}, {stageId=2, tasks=1, fullGcTasks=0, minFullGcSec=0, maxFullGcSec=0, totalFullGcSec=0, averageFullGcSec=0}]",
    "outputBufferUtilization": "[{stageId=0, tasks=1, p01=0.0, p05=0.0, p10=0.0, p25=0.0, p50=0.0, p75=2.30083448689341E-4, p90=3.0994415283203125E-4, p95=3.0994415283203125E-4, p99=3.0994415283203125E-4, min=0.0, max=3.0994415283203125E-4, duration=0.010681886}, {stageId=1, tasks=1, p01=0.0, p05=0.0, p10=0.0, p25=0.0, p50=6.22467014518136E-5, p75=4.163024838600526E-4, p90=5.006790161132812E-4, p95=5.006790161132812E-4, p99=5.006790161132812E-4, min=0.0, max=5.006790161132812E-4, duration=0.013562824}, {stageId=2, tasks=1, p01=0.0, p05=0.0, p10=0.0, p25=0.0, p50=1.5597716669174048E-4, p75=5.968228705004009E-4, p90=6.318092346191406E-4, p95=6.318092346191406E-4, p99=6.318092346191406E-4, min=0.0, max=6.318092346191406E-4, duration=0.018201713}]",
}

This maybe okay for human, but not suitable for handling by a software, as this requires adding custom parsers.

• Some fields in trino_query_statistics are JSON-serialized strings inside OpenLineage event JSON:
  

  trino/core/trino-spi/src/main/java/io/trino/spi/eventlistener/QueryStatistics.java

  Lines 80 to 90 in c36815a

  	/**
  	* Operator summaries serialized to JSON. Serialization format and structure
  	* can change without preserving backward compatibility.
  	*/
  	private final Supplier<List<String>> operatorSummariesProvider;
  	private final List<QueryPlanOptimizerStatistics> optimizerRulesSummaries;
  	/**
  	* Plan node stats and costs serialized to JSON. Serialization format and structure
  	* can change without preserving backward compatibility.
  	*/
  	private final Optional<String> planNodeStatsAndCosts;

  
  Instead, it could be a nested JSON object.