fix: SASS deprecation warning on tabulator themes

[thisjt]

While developing some of my apps that uses tabulator, these warnings started showing up:

This PR will fix these deprecation warnings by moving the border stylings from below the .tabulator-row class to above it. I'm assuming this will not impact anything as the styles being changed inside .tabulator-row is not manipulating border stylings. However, if there's a reason why it was placed below, then let me know and I can modify it so that we can follow this style declaration suggested by the SASS documentation:

Here's some more info on this SASS breaking change: https://sass-lang.com/documentation/breaking-changes/mixed-decls/