Improve Precision to 10 microseconds in timespan (dotnet/coreclr#24279)
Improve Precision to 10 microseconds in timespan (dotnet/coreclr#24279)

* Increasing precision properly and leaving the rounding of to casting operator

* disabling corefx tests in coreclr and addressing feedback

* correcting test project name

* Fix json

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

ViktorHofer/corefx,BrennanConroy/corefx,ViktorHofer/corefx,wtgodbe/corefx,BrennanConroy/corefx,ericstj/corefx,ericstj/corefx,wtgodbe/corefx,ericstj/corefx,ericstj/corefx,wtgodbe/corefx,ViktorHofer/corefx,shimingsg/corefx,shimingsg/corefx,shimingsg/corefx,BrennanConroy/corefx,ViktorHofer/corefx,shimingsg/corefx,ViktorHofer/corefx,shimingsg/corefx,ViktorHofer/corefx,ViktorHofer/corefx,wtgodbe/corefx,ericstj/corefx,wtgodbe/corefx,wtgodbe/corefx,wtgodbe/corefx,shimingsg/corefx,ericstj/corefx,ericstj/corefx,shimingsg/corefx