Investigate using a custom file upload file instead of the browsers

[buren]

Currently we use the native, browser, file upload field and that will not be localized (will just use whatever language the browser is in).

We should instead style our own.

Examples

• http://geniuscarrier.com/how-to-style-a-html-file-upload-button-in-pure-css/
• https://codepen.io/wallaceerick/pen/fEdrz

Extracted this issue out from https://github.com/justarrived/just-match-frontend/issues/656.