Hide file contents of private files for streaming

[mikayla-maki]

Currently, there is a short delay when opening configuration files for the first time while the tree sitter grammar loads. This can cause redacted values to be temporarily visible, which is bad when every frame is being recorded There are also files that should not be visually shared that aren't simple configuration files, like keys and certs. We should implement a system to hide the entire contents of a private file unless the redactions are fully functional, and/or preload treesitter grammars that support the redaction query.