The apostrophe does not seem to be a mistake. Every single hit that google returns has the apostrophe.
However, the capital N, although in (almost) every result from Dickens, does not seem to be necessary. There are precious little other occurrences of this phrase, but this New-Zealand paper from 29 June 1872 seems to ascertain that the expression fits in a Suffolk dialect:
Poaching v. Preaching.
— Rector : “Good Morning Mr. Catchpole ! I'm Sorry that I See you now so seldom at our Service !”
— Gamekeeper (Suffolk) : “Well, Sir, all I can Shay is, if the N'ghbours knowed as I were rig lar at the Chu'ch, you'd be 'nation sure to Lewse pretty nigh Half yar Congregation !”
(I tried to copy the original text as faithfully as possible, bold mine).
As to the meaning, 'nation just seems to mean very, as in you can be very sure, although I cannot find many instances of it being used...
As others suggest, it may well be an alternative shortening of damnation.
Etymonline shows that damnation was used as imprecation (spoken curse) from the 16th century.
For damn, the same source mentions that the explitive is from the 14th century.
Based on that, it seems the verb damn lead to the now still common expletive, but that at least for some time, the form (dam)nation was used instead, or next to it, similar in meaning, which, in print, may be explained by this (same source):
Damn and its derivatives generally were avoided in print from 18c. to c.1930s
So if Dickens wanted to avoid damn, chances were, 'Nation would be well-understood and serve the same purpose. :)