doc: add fullName property to SuiteContext

Add documentation for the missing fullName property in SuiteContext class.
This property returns the name of the suite and each of its ancestors,
separated by '>'.

The property has been available since v22.3.0 but was missing from the
documentation.

Fixes: #60757

Author: PaulyBearCoding

doc/api/test.md

@@ -3970,6 +3970,14 @@ The absolute path of the test file that created the current suite. If a test
 file imports additional modules that generate suites, the imported suites will
 return the path of the root test file.
 
+### `context.fullName`
+
+<!-- YAML
+added: v22.3.0
+-->
+
+The name of the suite and each of its ancestors, separated by `>`.
+
 ### `context.name`
 
 <!-- YAML