Implement File -> Delete Tag

[cyclops1982]

Delete a single tag from a File.

Input values:

• File Id (Text)
• Name of tag (Text)

Expected output:

• Same as GetInfoById (with updated tags)

Input validation:
If the file does not exist: "File '{Id}' does not exist."
If the tag does not exist, simply ignore it. This means you can run the method multiple times without errors.