Clean up gitignore files to have one at root of project

[B-Teague]

Ran into issue with running cargo test --release generating new binary files that were not being ignored properly because the file case did not match the case in the gitignore file in the same directory.

Would look to consolidate the ignored files to a single ignore file at the root of the project directory based on file extensions and directories and at this at the top to handle binary files with no extension.

#Do not modify these first three ignore rules.  Needed to ignore files with no extension
# Ignore all files including binary files that have no extension
*
# Unignore all files with extensions
!*.*
# Unignore all directories
!*/

# Add specific file extensions and directories below

[Anton-4]

Ignoring all files without extension sounds like a good idea but I'm not sure about using a single gitignore file, I'll ask on zulip.