Enabled HTML formatting for flashMessages

[dariobanfi]

As part of #878 (comment), successfully merged through #928 you enabled html formatting in error/success messages.

However this only work only through languageDictionary strings and not when the message is called through: lock.show({flashMessage: {...})

This small change should fix that.

[dariobanfi]

(Failing tests shouldn't be because of my change I think... I just cloned the latest master)

[luisrudge]

I triggered a rebuild. In the meantime, can you add a test for this? Thanks for the PR!

[dariobanfi]

@luisrudge I added some component tests

[luisrudge]

Hi @dariobanfi the tests are failing because you changed the way you render errors.
We validated https://github.com/auth0/lock/blob/f82d025fd9015d7e381174657f38e850d6dd1e69/test/mfa_ro.ui.test.js#L85 that the error was shown using this helper function. You should make sure the tests reflect the change you made and they pass. Let me know if you need more help. Thanks again for the PR!

[dariobanfi]

I updated the PR.
The problem with tests was caused by an inconsistency on how GlobalMessage message prop was passed, sometimes it was a React component (when using i18n strings) and sometimes a string (when using flashMessage).
I changed so that it's always passed as React component.

[luisrudge]

Thanks for the PR @dariobanfi 🎉