Added Ignore Image Files Option to UUID BCheck

[alp1n3-eth]

This is a fix in reference to the following issue: #193

I've added the configuration option to ignore the content-types related to the following image files: gif, png, jpeg, svg+xml. More can be added, in original issue request they reference it hitting on .exe files, but I could only find files with valid FP hits for the above extensions and not an .exe. If needed, I can throw that check in there as well, but I wanted to keep this as "realistic" as possible and only added checks for FP hits that I observed and could therefore test against.

BCheck Contributions

• [x] BCheck compiles and executes as expected
• [x] BCheck contains appropriate metadata (name, version, author, description and appropriate tags)
• [x] Only .bcheck files have been added or modified
• [x] BCheck is in the appropriate folder
• [x] PR contains single or limited number of BChecks (Multiple PRs are preferred)
• [x] BCheck attempts to minimize false positives