IconFamilyType do not reflect accepted values defined in getIconType helper

[aayush123]

Describe the bug
IconFamilyType forces Icon's family ty'pe to accept values such as 'EvilIcons', 'FontAwesome' etc, however, getIconType helper accepts values such as 'evilicons', 'font-awesome' etc, due to which, default case, ie. MaterialIcon is returned always.

To Reproduce
Steps to reproduce the behaviour:

1. Import Icon
2. Pass family as FontAwesome (as expected by TS declaration) and name as address-book.
3. See error

Expected behavior
FontAwesome's address-book icon should be visible.
Instead, no icon is identified and ? is displayed.

Additional context / Proposed Solution
Either the IconFamilyType should be updated to reflect actual accepted values, or getIconType should be updated to handle new values specified by IconFamilyType.
In my opinion, IconFamilyType should be updated as it will maintain backward compatibility and fix type issue also, as the new types are anyway buggy by nature.

Willing to submit PR for same.