Set model storage path via env var

[jason-meredith-rewind]

Summary:
As per the documentation found here: https://owasp.org/www-project-threat-dragon/docs-2/getting-started#opening-an-existing-model

Note that Threat Dragon is fairly strict on where the threat models can be stored. The threat models must be under a parent directory called ‘ThreatDragonModels’ and the JSON file must then be stored in a sub-directory with the same name as the model.
As an example, shown is a directory containing two models ‘test-reports’ and ‘New Threat Model’ under the directory ‘ThreatDragonModels’. This directory structure has been carried over from Threat Dragon versions 1.x, and in future it may become less strict.

I was hoping there would be a way of configuring where saved models are stored on a repo (ie in a /doc directory), and seeing this thought to add the functionality myself.

With this change, if no changes are made to the environment variables nothing changes in the directory structure - it is entirely opt-in and backwards compatible. If you would like to customize where models are stored, you can now set the REPO_ROOT_DIRECTORY environment variable. You can also override it per platform, ie GITHUB_REPO_ROOT_DIRECTORY, BITBUCKET_REPO_ROOT_DIRECTORY, etc.

Description for the changelog:

Customizable model storage path

[jgadsden]

many thanks for this @jason-meredith-rewind and ignore one of the broken tests (Desktop e2e) as this is a known issue
Could you have a look at the server unit tests? These should run OK so I guess the changes need some fixups in the unit tests
You can run the server unit tests by themselves with npm run test:server

[jason-meredith-rewind]

@jgadsden Yes for sure, I will take a look and fix those. Thanks!

[jgadsden]

many thanks for this @jason-meredith-rewind
all good to merge