Add font(in:) and format(in:) functions

[MaxDesiatov]

Resolve #134

[MaxDesiatov]

@CMiller3 would you mind having a quick look at the diff? Please let me know if this API makes sense. 🙂

[codecov]

Codecov Report

Merging #135 (158076b) into main (e390c57) will increase coverage by 0.05%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main     #135      +/-   ##
==========================================
+ Coverage   97.00%   97.05%   +0.05%     
==========================================
  Files           9        9              
  Lines         300      306       +6     
==========================================
+ Hits          291      297       +6     
  Misses          9        9              

Impacted Files	Coverage Δ
Sources/CoreXLSX/Worksheet/CellQueries.swift	91.17% <100.00%> (+1.89%)	⬆️
Sources/CoreXLSX/XLSXFile.swift	96.72% <100.00%> (ø)

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[CMiller3]

I really have no business giving opinions on this -- but yeah man, definitely helps clarify what to expect from the API! Thanks for the swift fixes ;)