Add config option for transcendental BASIC functions

Also move all transcendental functions to a separate source directory
Turn off these functions for all configurations for now

src/basic/math_trans/e264.cos_FAC1.s

@@ -0,0 +1,28 @@
+;; #LAYOUT# STD *       #TAKE
+;; #LAYOUT# *   BASIC_0 #TAKE
+;; #LAYOUT# *   *       #IGNORE
+
+;
+; Math package - cosine of FAC1 in radians
+;
+; Adds pi/2 to FAC1 and falls through to the sine function
+;
+; See also:
+; - [CM64] Computes Mapping the Commodore 64 - page 210
+; - https://www.c64-wiki.com/wiki/Floating_point_arithmetic
+; - https://codebase64.org/doku.php?id=base:kernal_floating_point_mathematics
+;
+
+
+!ifdef CONFIG_TRANSCENDENTAL_FUNCTIONS {
+
+
+COS:
+    ldy #>const_HALF_PI
+    lda #<const_HALF_PI
+    jsr add_MEM_FAC1
+    
+    ; FALLTHROUGH to SIN
+
+
+}