Make attribute name for <code> and <blockcode> tags configurable

- Currently, the geshifilter module uses and . The htmlfilter module as of 4.7.3 removes the type attribute from both tags.

- I'd like to use language instead because "type" is not as intuitive and imho even misleading because "type" is rather unspecific as to what property of the code it is supposed to describe.

It would be nice if I could change the name of this tag in the settings for this module!