Chore: Restructure test_app

[peter-marcisovsky]

The original ~/test_app folder containing all the test cases was removed. Now each folder from ~/host/class and ~/device has its own test_app with its own pytest_xxx_.py

Proposed structure with separate test apps:

tests with usb_host tag:

• pytest_usb_host_cdc.py
• pytest_usb_host_hid.py
• pytest_usb_host_msc.py
• pytest_usb_host_uvc.py

tests with usb_device tag:

• pytest_usb_device_esp_tinyusb.py
• pytest_usb_device_cdc.py

Tests with usb_host tag are run in CI . ├── device │   ├── dcd │   ├── esp_tinyusb │   │   └── test_app │   │      ├── main │   │      ├── pytest_usb_device_esp_tinyusb.py │   │      └── pytest_usb_device_cdc.py │   └── power_delivery ├── host │   ├── class │   │   ├── cdc │   │   │   ├── esp_modem_usb_dte │   │   │   ├── usb_host_cdc_acm │   │   │      └── test_app │   │   │         ├── main │   │   │         └── pytest_usb_host_cdc.py │   │   │   ├── usb_host_ch34x_vcp │   │   │   ├── usb_host_cp210x_vcp │   │   │   ├── usb_host_ftdi_vcp │   │   │   └── usb_host_vcp │   │   ├── hid │   │   │   ├── esp_hid_usb │   │   │   └── usb_host_hid │   │   │   └── test_app │   │   │      ├── main │   │   │      └── pytest_usb_host_hid.py │   │   ├── msc │   │   │   ├── usb_host_msc │   │   │   └── test_app │   │   │      ├── main │   │   │      └── pytest_usb_host_msc.py │   │   └── uvc │   │   ├── usb_host_uvc │   │     └── test_app │   │         ├── main │   │         └── pytest_usb_host_uvc.py │   └── usb_host_lib ├── otg └── usb_phy