[TASK] Resolve conflicts in "Var" ViewHelpers by rename to "Variable"

Aliases are in place but the new recommended usage of all variable type ViewHelpers is now:

```
{v:variable.set(name: 'foobar', value: 'bar')}

{v:variable.get(name: 'foobar.{dynamicIndex}')}
```

And so on. In other words, `v:var` is now `v:variable`.