* Issue 1596: runner throws nullref exception when writting env var
* Adding tests for missing new line after EOF marker
* Changing newline to new line
* First prototype of step summary environment variable
* Fix file contention issue
* Try to simplify cleaning up file references
* use step id as md file name, queue file attachment
* separate logic into attachment summary func
* Fix indentation
* Add (experimental) feature flag support
* reorganize summary upload determination logic
* file i/o exception handling + pr feedback
* Revert changes for now to reintroduce them later
* Add skeleton SetStepSummaryCommand
* Update step summary feature flag name
* Port ShouldUploadAttachment from previous iteration
* Port QueueStepSummaryUpload from previous iteration
* Improve exception handling when uploading attachment
* Add some minor logging improvements
* Refuse to upload files larger than 128k
* Implement secrets scrubbing
* Add TODO comment to remove debugging temp files
* Add first tests
* Add test for secret masking
* Add some naming/style fixes suggested in feedback
* inline check for feature flag
* Inline method for style consistency
* Make sure that scrubbed file doesn't exist before creating it
* Rename SetStepSummaryCommand to CreateStepSummaryCommand
* Fix error handling messages
* Fix file command name when registering extension
* Remove unnecessary file deletion
Co-authored-by: Rob Herley <robherley@github.com>
