Upgrade Kotlin to v1.8 across the board

[sdsantos]

Time to upgrade from Kotlin 1.6 to 1.8 across all libraries and apps. Here's the plan:

1. Upgrade Kotlin across all libraries and merge into the main branch.

• [x] awala-jvm
• [x] awala-testing-jvm
• [x] awala-poweb-jvm
• [x] awala-cogrpc-jvm
• [x] awala-cogrpc-okhttp-jvm
• [x] awala-keystore-file-jvm
• [x] awala-endpoint-android

2. Update the apps to use Kotlin 1.8 along with the latest versions of the Awala libraries.

• [x] awala-courier-android
• [x] awala-gateway-android
• [x] awala-ping-android

[gnarea]

Thanks! All looks good! 💪🏾

[Filmaluco]

PR opened for awala-poweb-jvm. Take a look, and mark it as done once approved @sdsantos

[Filmaluco]

PR opened for awala-endpoint-android Take a look, and mark it as done once approved @sdsantos