encapsulated changes in two macros: FIX_ISSUE_19666_PHASE_DIFF andf FIX_ISSUE_1966_F0_32BIT

#define FIX_1521_SBA_LOUDNESS_STEREO                    /* FhG: issue 1521: Fix loudness for SBA to stereo rendering */

#define FIX_1559                                        /* Eri/FhG: fix for Issue 1559 in FD CNG with bitrate/bw switching */

/*#define FIX_ISSUE_1966*/                              /* FhG: Basop issue 1966: shift phase range to [-2PI..+2PI[, handle 4 quadrants */

                                                        /* FhG: Basop issue 1966: use 32-bit variables for F0 and thresholdModification */

/* Macros for issue 1966 are independent, phase diff is always BE for EVS_MONO */

/* The changes for F0+thdModification are mainly for IVAS better float compatibility, */

/* for EVS_MONO, all is kept BE. */

#define FIX_ISSUE_1966_PHASE_DIFF                       /* FhG: Basop issue 1966: shift phase range to [-2PI..+2PI[, handle 4 quadrants */

#define FIX_ISSUE_1966_F0_32BIT                         /* FhG: Basop issue 1966: use 32-bit variables for F0 and thresholdModification */

/* ##################### End NON-BE switches ########################### */

/* ################## End MAINTENANCE switches ######################### */