Add Automated testing workflow

[locnnil]

• Added a test for the matter-pi-gpio-commander.test-blink application.
• Added a test for the lighting-app application using the Wi-Fi method.
• Utilized the GPIO Testing Driver to mock GPIOs.

[farshidtz]

Looks good, with some minor comments. Thanks

I tested it on a Raspberry Pi 5:

$ GPIO_CHIP=4 GPIO_LINE=4 go test -v -failfast -count 1
go: downloading github.com/stretchr/testify v1.8.4
go: downloading github.com/canonical/matter-snap-testing v1.0.0-beta.1
go: downloading github.com/davecgh/go-spew v1.1.1
go: downloading github.com/pmezard/go-difflib v1.0.0
go: downloading gopkg.in/yaml.v3 v3.0.1
2024/02/20 08:55:55 [CLEAN]
2024/02/20 08:55:55 [exec] sudo snap remove --purge matter-pi-gpio-commander
2024/02/20 08:55:59 [stdout] matter-pi-gpio-commander removed
2024/02/20 08:55:59 [exec] sudo snap remove --purge chip-tool
2024/02/20 08:55:59 [stderr] snap "chip-tool" is not installed
2024/02/20 08:55:59 [SETUP]
2024/02/20 08:55:59 [exec] sudo snap install matter-pi-gpio-commander --channel=latest/edge
2024/02/20 08:56:08 [stdout] matter-pi-gpio-commander (edge) 2.0.0 from Canonical IoT Labs installed
2024/02/20 08:56:08 [exec] sudo snap set matter-pi-gpio-commander gpiochip='4'
2024/02/20 08:56:08 [exec] sudo snap set matter-pi-gpio-commander gpio='4'
2024/02/20 08:56:08 [exec] sudo snap connect matter-pi-gpio-commander:avahi-control 
2024/02/20 08:56:09 [exec] sudo snap connect matter-pi-gpio-commander:bluez 
2024/02/20 08:56:10 [exec] sudo snap connect matter-pi-gpio-commander:network 
2024/02/20 08:56:10 [exec] sudo snap connect matter-pi-gpio-commander:network-bind 
2024/02/20 08:56:10 [exec] sudo snap connect matter-pi-gpio-commander:custom-gpio matter-pi-gpio-commander:custom-gpio-dev
=== RUN   TestBlinkOperation
    snap_test.go:205: [exec] sudo matter-pi-gpio-commander.test-blink
    exec.go:140: [stdout] GPIO: 4
    exec.go:140: [stdout] GPIOCHIP: 4
    exec.go:140: [stdout] On
    exec.go:140: [stdout] Off
    exec.go:140: [stdout] On
    exec.go:140: [stdout] Off
    exec.go:140: [stdout] On
    exec.go:140: [stdout] Off
    exec.go:140: [stdout] On
    exec.go:140: [stdout] Off
    exec.go:140: [stdout] On
--- PASS: TestBlinkOperation (5.00s)
=== RUN   TestWifiMatterCommander
    snap.go:28: [exec] sudo snap install chip-tool --channel=latest/edge
    exec.go:140: [stdout] chip-tool (edge) v1.2.0.1+snap from Canonical IoT Labs installed
2024/02/20 08:56:19 [exec] sudo snap connect chip-tool:avahi-observe 
    snap.go:161: [exec] sudo snap start --enable matter-pi-gpio-commander
    exec.go:140: [stdout] Started.
=== RUN   TestWifiMatterCommander/Commission
    snap_test.go:233: [exec] sudo chip-tool pairing onnetwork 110 20202021
    snap_test.go:235: stderr: 
=== RUN   TestWifiMatterCommander/Control
    snap_test.go:240: [exec] sudo chip-tool onoff toggle 110 1
    snap_test.go:240: [exec] sudo chip-tool onoff toggle 110 1
    snap_test.go:240: [exec] sudo chip-tool onoff toggle 110 1
    snap_test.go:240: [exec] sudo chip-tool onoff toggle 110 1
--- PASS: TestWifiMatterCommander (7.47s)
    --- PASS: TestWifiMatterCommander/Commission (0.78s)
    --- PASS: TestWifiMatterCommander/Control (1.75s)
PASS
2024/02/20 08:56:23 [TEARDOWN]
2024/02/20 08:56:23 [exec] (sudo journalctl --since "2024-02-20 08:55:55" --no-pager | grep "matter-pi-gpio-commander"|| true) > matter-pi-gpio-commander.log
Wrote snap logs to /home/ubuntu/matter-pi-gpio-commander/tests/matter-pi-gpio-commander.log
2024/02/20 08:56:23 [exec] rm 
2024/02/20 08:56:23 Removing installed snap: true
2024/02/20 08:56:23 [exec] sudo snap remove --purge matter-pi-gpio-commander
2024/02/20 08:56:29 [stdout] matter-pi-gpio-commander removed
2024/02/20 08:56:29 [exec] sudo snap remove --purge chip-tool
2024/02/20 08:56:33 [stdout] chip-tool removed
2024/02/20 08:56:33 [exec] ./gpio-mock.sh teardown
ok  	matter-pi-gpio-commander-tests	38.208s