Keyword "SomeKeyword" already exists: Process existing keyword

When the keyword entered into the form already exists the user receive the following notice: Keyword "Somekeyword" (eg. Soothers) already exists.
A keyword could be in the keyword table if it exists in in a vocabulary or was submitted previously. A function in custom_shops checks to see if the keyword submitted via the keyword search form matches a taxonomy term or a previously submitted keyword.

We need to create function to ensure that when a keyword is submitted which is already in the keyword table it gets processed immediately (create parent node).