Fix #128 - provide default values when filteredContent.meta is empty.

[ruzz311]

I ran into this issue as well when extending models-table-server-paginated but decided to PR the change proposed by @gossi

[onechiporenko]

@ruzz311, as for me, Serializer should handle BE-responses with models data and check if meta exists

[ruzz311]

I'm fairly new to how ember does things but I requested this change to help with various component integration testing. I've extended the server-pagination component and we have a more complex version that fails on render tests with out us being overly explicit.

Maybe there's a better way since the only time this is a problem for me is in tests; a common DS mock suite perhaps? Regardless, I do believe handling unexpected inputs in a graceful way with low of effort might make this component stronger.

[ruzz311]

@onechiporenko - Really appreciate this merge. Our app is evolving and I'm sure we'll end up using Mirage like you are for the docs but we just haven't written enough yet.

I'm slowly PR'ing things I've been doing to extend the base functionality of the server-paginated, so if the next few look a little out there or aren't what you want on your roadmap let me know.

[onechiporenko]

Ok, @ruzz311. Thank you