Remove references to the 'depends' property outside of Task.cpp

With the exception of `taskDifferences` and `taskInfoDifferences`,
deferred to #2572.

src/commands/CmdEdit.cpp

@@ -667,7 +667,8 @@ void CmdEdit::parseTask (Task& task, const std::string& after, const std::string
   value = findValue (after, "\n  Dependencies:");
   auto dependencies = split (value, ',');
 
-  task.remove ("depends");
+  for (auto& dep : task.getDependencyUUIDs ())
+    task.removeDependency (dep);
   for (auto& dep : dependencies)
   {
     if (dep.length () >= 7)

src/commands/CmdInfo.cpp

@@ -147,7 +147,7 @@ int CmdInfo::execute (std::string& output)
 
     // dependencies: blocked
     {
-      auto blocked = dependencyGetBlocking (task);
+      auto blocked = task.getDependencyTasks ();
       if (blocked.size ())
       {
         std::stringstream message;
@@ -162,7 +162,7 @@ int CmdInfo::execute (std::string& output)
 
     // dependencies: blocking
     {
-      auto blocking = dependencyGetBlocked (task);
+      auto blocking = task.getBlockedTasks ();
       if (blocking.size ())
       {
         std::stringstream message;

src/commands/CmdPurge.cpp

@@ -71,8 +71,7 @@ void CmdPurge::handleDeps (Task& task)
    for (auto& blockedConst: Context::getContext ().tdb2.all_tasks ())
    {
      Task& blocked = const_cast<Task&>(blockedConst);
-     if (blocked.has ("depends") &&
-         blocked.get ("depends").find (uuid) != std::string::npos)
+     if (blocked.hasDependency (uuid))
      {
          blocked.removeDependency (uuid);
          Context::getContext ().tdb2.modify (blocked);