Allow user to set appropriate content-type on parameters > key/value pairs tab of scrapeable file

When a user sets a post parameter type as "File", it would be very useful if they could also set the Content-Type for that file, for example:

application/java-archive
application/EDI-X12
application/EDIFACT
application/javascript
application/octet-stream
application/ogg
application/pdf
application/xhtml+xml
application/x-shockwave-flash
application/json
application/ld+json
application/xml
application/zip
application/x-www-form-urlencoded
audio/mpeg
audio/x-ms-wma
audio/vnd.rn-realaudio
audio/x-wav
image/gif
image/jpeg
image/png
image/tiff
image/vnd.microsoft.icon
image/x-icon
image/vnd.djvu
image/svg+xml
text/css
text/csv
text/html
text/javascript (obsolete)
text/plain
text/xml
video/mpeg
video/mp4
video/quicktime
video/x-ms-wmv
video/x-msvideo
video/x-flv
video/webm