Upload the chart image to a github repo - and a few other changes

[x] DRY_RUN environment variable to only log the comment message instead of posting
[x] Image will now be uploaded to a specific github repo and referred in the comment message
[x] SQL query are now being executed in parallel
[x] Add retry on SQL query in case of peer disconnected
[x] All external strings should be escaped when putting into markdown
[x] Add a environment variable to allow use fake link instead of real link - so that the actual issue won't get mentioned in a testing environment
[x] Integration with AWS lambda

data-preservation-programs / filplus-checker