Build filetree with missing directories to support --only-findings scans

[OmkarPh]

Fixes #404 #393

• Handles scans with --only-findings option by imputing required intermediate directories
• Fixed root path resolution for cases like empty scans.

Reference scans -
allsamples-onlyfindings.json.txt
allsamples-onlyfindings-noresources.json.txt

[AyanSinhaMahapatra]

@OmkarPh thanks++
Looks good and needs a couple more edge-cases handling, based on problems detected in larger scans.

Consider the following scans:

postgresml-2.8.1.json
postgresml-2.8.1-only-findings.json

See comments below:

1. In the only-findings scan, the file-tree is not behaving correctly for nested directories (as the corresponding parent directories are missing?) should we populate missing parent directories ourself while importing the scan? Example resource: "postgresml-2.8.1/pgml-cms/docs/resources/benchmarks/mindsdb-vs-postgresml.md" this is not present in the file tree on the left. And the expand directory icon also hangs for some reason?
2. In your allsamples-onlyfindings-noresources.json.txt example, when we import this, nothing happens are there are no resources. I would like to see something to indicate that there was no resources in the scan and so we can't show anything.

[OmkarPh]

1. In the only-findings scan, the file-tree is not behaving correctly for nested directories (as the corresponding parent directories are missing?) should we populate missing parent directories ourself while importing the scan? Example resource: "postgresml-2.8.1/pgml-cms/docs/resources/benchmarks/mindsdb-vs-postgresml.md" this is not present in the file tree on the left. And the expand directory icon also hangs for some reason?

Thank you for pointing this out, there was an issue with handling files in batches (for large scans)
I've fixed it. Should work fine now, see

[OmkarPh]

2. In your allsamples-onlyfindings-noresources.json.txt example, when we import this, nothing happens are there are no resources. I would like to see something to indicate that there was no resources in the scan and so we can't show anything.

Sure, I'll add a warning/error snackbar with this message
But, should we abort importing such scans or load all views with empty data?

[AyanSinhaMahapatra]

But, should we abort importing such scans or load all views with empty data?

If there's no data at all (here I mainly mean no file data, as other codebase level attributes are atleast option-dependent) there's no use showing empty views, so it's fine if we abort importing and show the message there.

[OmkarPh]

Thanks for the feedback @AyanSinhaMahapatra
I've updated the PR

[AyanSinhaMahapatra]

@OmkarPh LGTM! Thanks++
The issues mentioned above are fixed now and this is ready to merge.
Please release too 🚀