fix: align stats/base/dists/cauchy/quantile validation prologue with namespace majority

Reorder NaN guards in the public quantile so that `isnan( gamma )` precedes
`isnan( x0 )`, matching the contiguous validation pattern present in 7 of the
9 sibling packages in `@stdlib/stats/base/dists/cauchy/*` (78% conformance).
Behavior is unchanged: any matching branch returns `NaN`.

Author: claude

lib/node_modules/@stdlib/stats/base/dists/cauchy/quantile/lib/main.js

@@ -74,8 +74,8 @@ var PI = require( '@stdlib/constants/float64/pi' );
 */
 function quantile( p, x0, gamma ) {
 	if (
-		isnan( x0 ) ||
 		isnan( gamma ) ||
+		isnan( x0 ) ||
 		gamma <= 0.0 ||
 		isnan( p ) ||
 		p < 0.0 ||