[pkg/ottl] Implement MarshalLogObject for the ottlmetric context

[edmocosta]

Component(s)

pkg/ottl

Is your feature request related to a problem? Please describe.

The MarshalLogObject(encoder zapcore.ObjectEncoder) function is used by the logger library to print out the TransformContext value. It's currently implemented for all other contexts, but not for metrics, leading debug logs to print empty values:

initial TransformContext before executing StatementSequence	{"TransformContext": {}}

Describe the solution you'd like

Similar to other contexts implementations, so the debug logs will properly print it out.

Describe alternatives you've considered

No response

Additional context

No response

[github-actions]

Pinging code owners:

• pkg/ottl: @TylerHelmuth @kentquirk @bogdandrutu @evan-bradley @edmocosta

See Adding Labels via Comments if you do not have permissions to add labels yourself.

[odubajDT]

Hi, I can take a look at this issue