[KloadGen]: Allow use of variables in plain text

[dianaGomezGar]

What happened?

As a developer, I want to send Jmeter variables as a plain text without schema.

If I get a Jmeter variable, I want to generate a result value in plain text with the value of the variable.

Value	Result
Text value	Result with same text value
Variable	Result with variable content

KloadGen Version

KloadGen 5.1.1

Relevant log output

No response

Have you added your JMX Testplan or a replica?

• [X] I have added a JMX testplan

Have you added your Schema or a replica?

• [X] I have added the Schema