Bug 12627: SQLHelper replacement - C4::Suggestions

Bug 12627: SQLHelper replacement - C4::Suggestions

With this patch, the subroutines NewSuggestion and ModSuggestion use DBIx::Class instead of C4::SQLHelper.
Moreover, the tests and the .pl have been adapted.

Test plan:
1) Apply the patch.

2) Execute the unit tests by launching :
prove t/db_dependent/Suggestions.t

3) The result has to be a success without error or warning :
t/db_dependent/Suggestions.t .. ok
All tests successful.
Files=1, Tests=91,  2 wallclock secs ( 0.05 usr  0.01 sys +  1.65 cusr  0.09 csys =  1.80 CPU)
Result: PASS

4) Log in the intranet, create a suggestion and verify the created suggestion.

5) Edit a suggestion from the intranet and verify the suggestion is correctly modified.

6) Log in the OPAC and verify you can add a suggestion.

Signed-off-by: Bernardo Gonzalez Kriegel <bgkriegel@gmail.com>
Test pass, suggestion created on staff and opac,
suggestion edited without problems, no koha-qa errors.

Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Passes tests and QA script:
Also tested:
- adding suggestion from staff and OPAC
- edit suggestion from staff
- deleting suggestion from OPAC
- changing to a normal status (email got created)
- changing to a custom status (SUGGEST_STATUS)
- display of custom status in OPAC

No problems found.

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>