collect all import errors before exiting

[zvif-orca]

Required Functionality
When attempting to import a database the could be potentially more than a single issue.
Exiting after the first import issue can be frustrating as a single issue may hide many others.
The import should keep running, keep collecting errors and finally exit with a list of problems.

Proposed Solution

• Collect errors to array during the import
• Before dumping the scheme, check if the array is not empty
• Finally exit listing all the collected import errors

Use case
I have few postgres DBs, I got unimplemented converter errors - one on each DB.
I had to write small script that collects all columns types from all the DBs and look at Synth source to understand which other types are yet supported, as the first error is masking the others.
Potentially, there could be other errors except unsupported columns, so the adaptation of Synth to my DBs could last for long time.