Merge branch 'feature/isDark' into 'develop'

added color extension for isDark

### Summary
(a brief description of the change)

### JIRA Ticket
(ticket URL here or remove the section)

Co-authored-by: Matt Bruce <matt.bruce@verizon.com>

See merge request https://gitlab.verizon.com/BPHV_MIPS/mvm_core_ui/-/merge_requests/998

MVMCoreUI/Categories/UIColor+MFConvenience.h

@@ -183,8 +183,12 @@
 // Returns a gradient lighter color;
 + (nonnull UIColor *)mfGradientColor:(nullable UIColor *)color;
 
+// Returns if the color is dark or not
+- (BOOL)isDark;
+
 #pragma mark - Hex String
 
 + (nullable NSString *)hexStringForColor:(nonnull UIColor*)color;
 + (nonnull UIColor *)mfGetColorForHexWithTransparency:(nonnull NSString *)hexString;
+
 @end

MVMCoreUI/Categories/UIColor+MFConvenience.m

@@ -389,6 +389,12 @@
     return [UIColor whiteColor];
 }
 
+- (BOOL)isDark {
+    CGFloat greyScale = 0;
+    [self getWhite:&greyScale alpha:nil];
+    return greyScale < 0.5;
+}
+
 #pragma mark - Hex String
 
 + (nullable NSString *)hexStringForColor:(nonnull UIColor*)color {