feat(pagination): add currentPageText prop

[bmestanov]

Hi, I'm using i18n for a project and it looks like the part of the Pagination component reading Showing X-Y of Z is hardcoded, so I came up with a prop that allows custom formatting of the text given X, Y, Z.

Cheers.

[codecov]

Codecov Report

Merging #17 (ed1ee00) into master (1b53901) will not change coverage.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##            master       #17   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           29        29           
  Lines          495       497    +2     
  Branches        77        77           
=========================================
+ Hits           495       497    +2     

Flag	Coverage Δ
unittest	100.00% <100.00%> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
src/Pagination.tsx	100.00% <100.00%> (ø)

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[estevanmaito]

Hey! This looks fantastic and its something that was annoying me. I'll take a better look on the weekend.

Thanks for the test too 👍