allow dapps to specify config for exporting private keys

[arch1995]

Motivation and Context

Allowing dapps to specify that they want to enable private key export or not.

Jira Link: https://toruslabs.atlassian.net/browse/PD-3834

Description

• Fetch the project config from dashboard and set it accordingly in the provider.
• Allow the dapps to enable/disable it via config setting.
• default value is true, hence allows exporting of private keys

How has this been tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

• My code follows the code style of this project. (run lint)
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.

[chaitanyapotti]

lgtm