support for custom propTypes with isRequired in no-typos

[lfades]

fixes: #1607 and helps in #1389.

if will add support for the following cases:

{
  a: string.isRequired,
  b: customProp.isRequired,
  // added support for isRequired in call expressions. No validation is done inside
  c: PropTypes.shape({
    d: string
  }).isRequired
  e: customShape({
    f: number
  }).isRequired
}

for a custom prop type like string.isrequired the error message will be: Typo in declared prop type: isrequired because currently it doesn't know that it's a prop type cualifier

for call expressions like customShape({}).isrequired the error message will be Typo in prop type chain qualifier: isrequired and it will work as long as it's not something like customShape().number.isRequired

[ljharb]

please add another test like this that uses the default parser

[ljharb]

same with these 2 tests; please duplicate them so there's 1 for babel-eslint and 1 for the default parser.