cleanup: Map test files according to structure in src

For example cmd_account() is located in src/command/cmd_funcs.c.
The unit test was located in tests/unittests/test_cmd_account.c.
Let's move it to a subdirectory like tests/unittests/command/test_cmd_account.c
to correpsond to the same structure.

tests/unittests/tools/test_autocomplete.h

@@ -0,0 +1,16 @@
+void clear_empty(void** state);
+void reset_after_create(void** state);
+void find_after_create(void** state);
+void get_after_create_returns_null(void** state);
+void add_one_and_complete(void** state);
+void add_two_and_complete_returns_first(void** state);
+void add_two_and_complete_returns_second(void** state);
+void add_two_adds_two(void** state);
+void add_two_same_adds_one(void** state);
+void add_two_same_updates(void** state);
+void complete_accented_with_accented(void** state);
+void complete_accented_with_base(void** state);
+void complete_both_with_accented(void** state);
+void complete_both_with_base(void** state);
+void complete_ignores_case(void** state);
+void complete_previous(void** state);