Version: Use int.TryFormat & StringBuilder.Append(int) (#15132)
Version: Use int.TryFormat & StringBuilder.Append(int) (#15132)

Now that `int.TryFormat` is available, along with the more efficient
`StringBuilder.Append(int)`, use them in `Version`.

Signed-off-by: dotnet-bot-corefx-mirror <03c4cb6107ae99956a7681f2c97ff7104809a2bd@microsoft.com>

zhenlan/corefx,wtgodbe/corefx,shimingsg/corefx,ptoonen/corefx,ptoonen/corefx,ViktorHofer/corefx,Ermiar/corefx,ptoonen/corefx,shimingsg/corefx,mmitche/corefx,ViktorHofer/corefx,zhenlan/corefx,wtgodbe/corefx,zhenlan/corefx,Jiayili1/corefx,shimingsg/corefx,wtgodbe/corefx,zhenlan/corefx,Ermiar/corefx,shimingsg/corefx,shimingsg/corefx,Jiayili1/corefx,ravimeda/corefx,ViktorHofer/corefx,ViktorHofer/corefx,Jiayili1/corefx,ericstj/corefx,ptoonen/corefx,Jiayili1/corefx,mmitche/corefx,ravimeda/corefx,BrennanConroy/corefx,mmitche/corefx,wtgodbe/corefx,shimingsg/corefx,ViktorHofer/corefx,Jiayili1/corefx,Ermiar/corefx,mmitche/corefx,Ermiar/corefx,ptoonen/corefx,shimingsg/corefx,ravimeda/corefx,mmitche/corefx,mmitche/corefx,Ermiar/corefx,ViktorHofer/corefx,BrennanConroy/corefx,ravimeda/corefx,ViktorHofer/corefx,Jiayili1/corefx,Jiayili1/corefx,wtgodbe/corefx,ericstj/corefx,ptoonen/corefx,zhenlan/corefx,zhenlan/corefx,ravimeda/corefx,wtgodbe/corefx,ericstj/corefx,Ermiar/corefx,Ermiar/corefx,ptoonen/corefx,mmitche/corefx,ericstj/corefx,ericstj/corefx,ravimeda/corefx,ericstj/corefx,BrennanConroy/corefx,ravimeda/corefx,zhenlan/corefx,ericstj/corefx,wtgodbe/corefx