Convert files with mostly LF line endings to pure LF
Convert files with mostly CRLF line endings to pure CRLF

This in order to make a full CRLF -> LF conversion easier to verify.
Convert files with only CRLF line endings to pure LF

These files intentionally remain with mixed line endings:

cors/resources/cors-headers.asis
html/semantics/embedded-content-0/the-canvas-element/size.attributes.parse.whitespace.html
html/syntax/parsing-html-fragments/the-input-byte-stream-034.html
html/syntax/parsing-html-fragments/the-input-byte-stream-037.html
html/syntax/parsing-html-fragments/the-input-byte-stream-038.html
old-tests/submission/Opera/media/track/webvtt/parsing/support/newlines.vtt
old-tests/submission/Opera/media/track/webvtt/parsing/support/signature-bom.vtt
old-tests/submission/Opera/media/track/webvtt/parsing/support/signature-two-boms.vtt