Starts a new XML node with the given name. Set root=true to clear out value.

Example:
| `Start XML Node`             | catalog           |
| `End XML Node`               |
| ${xmlString}                 | Create XML String |
| `Should Be Equal As Strings` | ${xmlString}      | <catalog/> |
| `Start XML Node`             | another-catalog   | true |
| `End XML Node`               |
| `Should Be Equal As Strings` | ${xmlString}      | <another-catalog/> |


Result:
| true
| true
