fix: webkit mask-composite values

[Olivia-SY129]

Fix for mask-composite prop values for webkit

Here are the changes:

'add' → 'source-over'
'substract' → 'source-out'
'intersect' → 'source-in'
'exclude' → 'xor'

Example for element.return:

before fix (not working in webkit)
'-webkit-mask-composite: add,intersect;mask-composite: add,intersect;'  

after fix
'-webkit-mask-composite: source-over,source-in;mask-composite: add,intersect;'

[thysultan]

@Olivia-SY129 can you add a test case, i'm assuming we can replace replaceAll with just replace safe assumption?