This commit adds a stress tests for creating multiple tasks with
xTaskCreateWithCaps such that the stack is allocated in external SPIRAM.
Then the tasks self-delete. This is done iteratively as stress test.
This commit adds the sdkconfig files for the FreeRTOS test app. These
configurations were dervied from the various legacy unit test app's
config files that included the FreeRTOS component.
This commit tries to keep a 1 to 1 config parity with the legacy test app.
Meaning, if FreeRTOS test were run on a particular target with a particular
config, that config will be represented in one of the test app's
sdkconfig.ci.XXX files.
However, the following configurations were removed for FreeRTOS tests:
- The "freertos_flash" option was removed due to redudancy (already tested in
freertos_options)
