Assertion message from JMESPathCheck is misleading when actual result evaluates to False.

[tobiasb-ms]

Describe the bug

When running scenario tests for an extension I'm writing, with a check like this:

self.cmd(f"az some_command --output json", checks=[
    self.check("thing", True)
])

The exception when the actual value of thing is False is misleading:

>           raise JMESPathCheckAssertionError(self._query, self._expected_result, 'None',
                                              execution_result.output)
E           azure.cli.testsdk.exceptions.JMESPathCheckAssertionError: Query 'thing' doesn't yield expected value 'True', instead the actual value is 'None'. Data:
E           {
E             "otherThing": "value",
E             "thing": false
E           }

It would be better in this case to say "the actual value is False".

We encounter similar issues with empty strings, empty lists, empty dictionaries, the number 0 and generally anything that evaluates to False.

I've created a pull request with more information about why this happens and a proposed fix.

Related command

azdev test

Errors

      raise JMESPathCheckAssertionError(self._query, self._expected_result, 'None',

                                          execution_result.output)

E azure.cli.testsdk.exceptions.JMESPathCheckAssertionError: Query 'thing' doesn't yield expected value 'True', instead the actual value is 'None'. Data:
E {
E "otherThing": "value",
E "thing": false
E }

### Issue script & Debug output

I feel this is unnecessary because the error message makes it clear (and see linked pull request).

### Expected behavior

The error message should say the real value of the actual result -- In the provided example, that would be `'False'`.

### Environment Summary

az --version
azure-cli                         2.63.0

core                              2.63.0
telemetry                          1.1.0

Extensions:
aks-preview                      7.0.0b3
azure-devops                       1.0.1
<redacted>                        0.0.1 (dev) /workspace/code/<redacted>/<redacted>/src/<redacted>

Dependencies:
msal                              1.30.0
azure-mgmt-resource               23.1.1

Python location '/workspace/code/<redacted>/<redacted>/.venv/bin/python'
Extensions directory '/home/<redacted>/.azure/cliextensions'
Development extension sources:
    /workspace/code/<redacted>/<redacted>

Python (Linux) 3.9.19 (main, Jul 31 2024, 03:47:41)
[GCC 11.2.0]

Legal docs and information: aka.ms/AzureCliLegal


Your CLI is up-to-date.

### Additional context

_No response_

[yonzhan]

Thank you for opening this issue, we will look into it.