doc: add fullName property to SuiteContext

Add documentation for the missing fullName property in SuiteContext.
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
PR-URL: #60762
Reviewed-By: René <contact.9a5d6388@renegade334.me.uk>
Reviewed-By: Ethan Arrowood <ethan@arrowood.dev>
Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com>
Reviewed-By: Chemi Atlow <chemi@atlow.co.il>

Author: PaulyBearCoding

doc/api/test.md

@@ -3662,7 +3662,9 @@ the path of the root test file.
 ### `context.fullName`
 
 <!-- YAML
-added: v22.3.0
+added:
+  - v22.3.0
+  - v20.16.0
 -->
 
 The name of the test and each of its ancestors, separated by `>`.
@@ -3965,6 +3967,16 @@ 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
+  - v20.16.0
+-->
+
+The name of the suite and each of its ancestors, separated by `>`.
+
 ### `context.name`
 
 <!-- YAML