TaskRepository basic unit tests

[opatry]

Description

Bootstrap TaskRepository CRUD unit tests & sync unit tests.
This is far from being completing but put in place the building blocks to ease new unit test addition.

Checklist

• I have read the CONTRIBUTING guide
• Code compiles correctly
• Created tests which fail without the change (if possible)
• All tests passing

[github-actions]

Job Summary for Gradle

Build & Test :: build

Gradle Root Project	Requested Tasks	Gradle Version	Build Outcome	Build Scan®
Taskfolio	:tasks-app-desktop:assemble	8.10.1	✅
Taskfolio	:tasks-app-android:assembleStoreRelease	8.10.1	✅
Taskfolio	test :tasks-app-android:testStoreReleaseUnitTest jvmTest	8.10.1	❌
Taskfolio	:tasks-app-android:exportLibraryDefinitions	8.10.1	✅
Taskfolio	:tasks-app-desktop:exportLibraryDefinitions	8.10.1	✅

[github-actions]

Job Summary for Gradle

Build & Test :: build

Gradle Root Project	Requested Tasks	Gradle Version	Build Outcome	Build Scan®
Taskfolio	:tasks-app-desktop:assemble	8.10.1	✅
Taskfolio	:tasks-app-android:assembleStoreRelease	8.10.1	✅
Taskfolio	test :tasks-app-android:testStoreReleaseUnitTest jvmTest	8.10.1	❌
Taskfolio	:tasks-app-android:exportLibraryDefinitions	8.10.1	✅
Taskfolio	:tasks-app-desktop:exportLibraryDefinitions	8.10.1	✅