Move from LegacyApiCore to ApiCore

[sv99]

I have some problems with sync plugin in my corporate wiki system. Some problems removed with new API.

But some files have mixed english and russian names on the my Mac. Directory are also.

Problems with russian letter CYRILLIC SMALL LETTER SHORT I which have two unicode representation.

U+000438 CYRILLIC SMALL LETTER I
U+000306 COMBINING BREVE
and
U+000439 CYRILLIC SMALL LETTER SHORT I

Need normalization procedure in the _sync function, when data prepared.