Optimize azdev test and azdev style

[wangzelin007]

1. Add some examples for azdev test.

2. When the extension name and module name are the same, let azdev style tests the extension instead of the main module.
   When executing azdev style containerapp, the base_name of the extension path is the same as the base_name of the module path.
   Module will execute _update_table before extension, and once hit, the remove operation will be executed.
   As a result, azdev style containerapp can never hit containerapp extension.
   So adjust the order of _update_table to ensure that extension is updated first.
   
   
   

3. Bug fixes for _detected_tested_command, strictly limited to starting with test and ending with .py or .yaml
   

[azure-client-tools-bot-prd]

Hi @wangzelin007,
Please write the description of change into HISTORY.rst.
If you want to release a new azdev version, please update the VERSION in init.py as well.