Merged the SearchFeedInputFilter validation & filter definitions

Normally this would make sense, as each element would likely need its
own definitions. But as the two elements share the same configuration
then it makes sense to merge them. These can be separated later if
there's cause to do so.
Specify the default feeds route as a class constant

This was done, replacing the previous functionality, because it's too
easy to make a mistake in one of the route strings. This way reduces the
likelihood of this happening.
fetchMostRecentFeeds limit parameter defaults to 5 when none supplied

It made sense to provide a sane default for the limit to allow it to be
called without mandating a parameter be passed.
Simplified the FeedTable save method

`getArrayCopy` did just what was being done by manually creating the
array from the FeedModel object. So it didn't make sense, on the surface
of it, to keep going this way. So I refactored to use `getarrayCopy``
instead. But I've left the original code in there as a suitable example.
Revise how a Paginator object is instantiated for Feeds

The previous way seemed repetitious and therefore incurred a maintenance
overhead that wasn't required. This way the paginator is sourced from a
central function and slims down the code required to use it in the
actions.
Stop setting form attributes in view template

This overrides the configuration in the form object, so would likely
lead to confusion and potential bugs which may be hard to track down. So
for this reason, it's being removed.
Remove unnecessary class namespacing
Merge branch 'feature/amend_feeds_controller' into develop