Replace loadData from ProfilePage with new parser

[nerocui]

The current method use xlsx.utils.sheet_to_json() which misses data when the cell is empty.
The new parseSheet function accept a csv variable and returns rich data about the result. Using it also makes the ProfilePage more loosely coupled with parser logic.
In order to use it, have loadData call sheet_to_csv instead and pass the csv to parseSheet in recordParser.js. The result will be returned and should be passed to this.props.importRecords() to push to redux. Then navigate to '/preview'.

Helper methods will also needed to be implemented. parseHeader and parseCell in recordParser.js

[nerocui]

branch is feature-import-preview