fix: freeze during file preview (#1836)

* fix: do not load binary content

License: MIT
Signed-off-by: Henrique Dias <hacdias@gmail.com>

* fix: smarter isBinary check

old one used 7 year old package that had hardcoded check of first 24
bytes, which was not always the best test.

istextorbinary one checks name and 24 bytes at the start, middle,
and end of the buffer – https://github.com/bevry/istextorbinary#readme

Co-authored-by: Marcin Rataj <lidel@lidel.org>