Better support for string values in search queries

[chandlerprall]

closes #1177

Summary

Addresses two string-related issues

• if a string value began with a number (e.g. 15m) it would be parsed only as the leading number
• if a non-string value (e.g. 15, true) was passed to a string-type field, it would fail to pass schema validation instead of being coerced to a string

Checklist

• This was checked in mobile
• This was checked in IE11
• This was checked in dark mode
• Any props added have proper autodocs
• Documentation examples were added
• A changelog entry exists and is marked appropriately
• This was checked for breaking changes and labeled appropriately
• Jest tests were updated or added to match the most common scenarios
• This was checked against keyboard-only and screenreader scenarios

[bevacqua]

🎉