As a user, I can obtain the Tests of a Test Execution by the "Executed by" field of Test Runs using a JQL function

As a user, I should be able to obtain, using JQL, the Tests of a Test Execution based on the "executed by" information of the respective Test Runs.
For that, the "testExecutionTests" should accept an additional optional parameter P5, such as:

P5 - User who executed Test Run (Optional). If you pass "" as argument then the function will basically ignore the parameter