Tool throws error, but the session was still getting saved leading to partial conversion

### Expected Behaviour
When tools throws error in conversion, the repository session should not be saved. This leads to partial conversion of the page.

### Actual Behaviour
Whenever tools throws any error while conversion, the session should not get saved.

### Reproduce Scenario (including but not limited to)
Add a non-existing component in the "order.components" page rewrite osgi configuration.
Once we run the page conversion, error would be thrown in error.log & status is shown as "failed" in the wizard.
Post that if we check the node structure in crx/de, we would see partial changes being saved there.

#### Steps to Reproduce
Add a non-existing component in the "order.components" page rewrite osgi configuration.
Once we run the page conversion, error would be thrown in error.log & status is shown as "failed" in the wizard.
Post that if we check the node structure in crx/de, we would see partial changes being saved there.

#### Platform and Version
Tool Version - 2.1.0

#### Sample Code that illustrates the problem

#### Logs taken while reproducing problem

Reproduce the failure by adding a non-existing component to the "order.components" page rewrite OSGi configuration and running page conversion. Trace where the conversion session is saved after the tool error; done means a failed conversion leaves no partial node changes in crx/de.

Written by the indexing model from the issue text.