Added squeeze_whitespace_keys, to squeeze spaces in the fields like Name

Added `squeeze_whitespace_keys`, so that spaces in fields like `full_name` can be squeezed.

For instance, if a user enters `full_name` as <pre>'  foo   bar  '</pre> then it will be stored as <pre>' foo bar '</pre> The user with `full_name` as <pre>' foo bar '</pre> will also be searchable by <pre>' foo   bar '</pre><br/><br/>If the `full_name` key is also added to `strip_whitespace_keys`, then it will strip the remaining leading and trailing spaces too.

So,<pre>'  foo   bar  '</pre> will be stored as <pre>'foo bar'</pre> The user with `full_name` as <pre>'foo bar'</pre> will also be searchable by <pre>'  foo   bar  '<pre>
please use the `swap` helper here, so the state of the `squeeze_whitespace_keys` is restored in the end of the test.