Add editqf_no_type_mappings to disable "types"

Related to #2. The IWE maps were bugging me so this lets me disable them. Might be useful to make them Plug maps too, but I like your new shift operators instead.

Possibly this should just use the same g:editqf_no_mappings flag instead.

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W and E are common motion commands that may be used in the quickfix
window, so add an option to prevent them from being mapped. The second
list of mappings we always want to map because they don't make sense in
the quickfix window (which is not modifiable).

For consistency, we also exclude I.