Rebrand 'map object' and 'field object' to 'event object'

graphics/event_objects/palettes/field_object_palette_21.pal

@@ -0,0 +1,19 @@
+JASC-PAL
+0100
+16
+0 123 197
+238 246 255
+222 230 238
+189 205 230
+156 164 189
+139 139 156
+98 98 123
+65 74 106
+197 98 98
+172 65 106
+0 0 0
+197 148 0
+246 213 24
+0 0 0
+0 0 0
+74 106 139