Fix PDF failed to load when the file URI contains an encoded accented character

[bernhardoj]

The decoding of the URI is currently done using unescape.

react-native-pdf/index.js

Line 238 in d545ff2

path: unescape(uri.replace(/file:\/\//i, '')),

However, this fails if the URI contains an encoded accented name, for example:

ù is encoded to %C3%B9, but decoding it using unescape gives ù.

This PR replaces unescape with decodeURIComponent.

[jjcoffee]

Possibly related issue #697. Also note that unescape is deprecated.