Move tests to relevant subprojects (#615)

- Moved test projects to the parent project they belong to
- Improved test stability/corectness
- Improved recursive directory deletion by safely ignoring current- and parent-directory entries.
- Update docs

Modules/crypt-module/tests/CMakeLists.txt

@@ -0,0 +1,16 @@
+project(CryptModuleTests)
+
+enable_language(C CXX ASM)
+
+file(GLOB_RECURSE TEST_SOURCES CONFIGURE_DEPENDS ${PROJECT_SOURCE_DIR}/source/*.cpp)
+add_executable(CryptModuleTests EXCLUDE_FROM_ALL ${TEST_SOURCES})
+
+target_include_directories(CryptModuleTests PRIVATE ${DOCTESTINC})
+
+add_test(NAME CryptModuleTests COMMAND CryptModuleTests)
+
+target_link_libraries(CryptModuleTests PUBLIC
+    crypt-module
+    TactilityKernel
+    freertos_kernel
+)