fix: missing parenthese when decompile cast operation

[khanhnt2]

Fix issue #1

I'm not familiar with Move language. I saw this repo on my social feeds, it's great to see Vietnamese people make the project 😄

My fix is always to add parentheses to cast operation, even though it's a stand-alone expression. Not sure this is a good solution

[khanhnt2]

Maybe I have to implement 'Ret' operation for the better solution

[vhqtvn]

We already added brackets for casting operator but need to revert at some point due to syntax error. I'll check it again.

[aquynh]

@khanhnt2, thank you for the first ever pull req!

can you put the new testcases into a new separate file, rather than adding them to BasicCoin-test.move?

[khanhnt2]

@aquynh, I moved the tests to the new CastOperation-test.move file

[aquynh]

merged, thanks!