Add TestExecutionScope and ThreadGroupScope variables, deprecate TestElement implements TestStateListener

### Use case

In many cases, test elements need "per-thread-group-scope" variable or "per-test-execution-scope" variable.
For instance:
* Timers use `static final Map`
* Summarizers might need their state as well
* DB connection pool might need to pool connections

The current approach of `element implements TestStateListener` causes issues like https://github.com/apache/jmeter/issues/6174, https://github.com/apache/jmeter/issues/6165

### Possible solution

We might need something like https://docs.gradle.org/current/userguide/build_services.html or https://github.com/google/guice/wiki/Scopes so the plugin authors can explicitly declare "per-test-execution state objects", so they do not need to implement `TestStateListener` in the test elements.

It might be worth deprecatign `TestElement implements TestStateListener` at least to discourage that usage pattern.

### Possible workarounds

_No response_

### JMeter Version

5.6.2

### Java Version

_No response_

### OS Version

_No response_