NumericInput: Fix Acceptable Formats

Summary:
Acceptable formats didn't work for numeric-input

Answers with no answer forms selected but "strictly match only these
formats" selected were impossible to answer. These now accept any format
of answer.

Test Plan:
Make a numeric-input in the answer area
[Example link](http://localhost:9000/test.html#content=%7B%22question%22%3A%7B%22content%22%3A%22a%5Cn%5Cnb%5Cn%5Cnc%5Cn%22%2C%22images%22%3A%7B%7D%2C%22widgets%22%3A%7B%7D%7D%2C%22answerArea%22%3A%7B%22type%22%3A%22multiple%22%2C%22options%22%3A%7B%22content%22%3A%22%5Cn%5Cn%5B%5B%E2%98%83%20numeric-input%201%5D%5D%22%2C%22images%22%3A%7B%7D%2C%22widgets%22%3A%7B%22numeric-input%201%22%3A%7B%22type%22%3A%22numeric-input%22%2C%22graded%22%3Atrue%2C%22options%22%3A%7B%22answers%22%3A%5B%7B%22value%22%3A42%2C%22status%22%3A%22correct%22%2C%22message%22%3A%22%22%2C%22simplify%22%3A%22required%22%2C%22answerForms%22%3A%5B%5D%2C%22strict%22%3Afalse%2C%22maxError%22%3Anull%7D%5D%2C%22size%22%3A%22normal%22%7D%7D%7D%7D%2C%22calculator%22%3Afalse%7D%2C%22hints%22%3A%5B%5D%7D)
 * Check that hovering over acceptable formats works for various format
   selections
 * Check that grading works even if no forms are selected and strict is
   checked

Auditors: eater