Bug 23420: (QA follow-up) Remove more AllowPurchaseSuggestionBranchChoice code

Test plan:
1. git grep -i AllowPurchaseSuggestionBranchChoice **/*.pm **/*.pl **/*.t
2. There should no longer be any code related to the old sys pref AllowPurchaseSuggestionBranchChoice

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>

C4/UsageStats.pm

@@ -266,7 +266,6 @@ sub BuildReport {
         ShowReviewerPhoto
         SocialNetworks
         suggestion
-        AllowPurchaseSuggestionBranchChoice
         OpacAllowPublicListCreation
         OpacAllowSharingPrivateLists
         OpacRenewalAllowed

opac/opac-suggestions.pl

@@ -219,20 +219,6 @@ foreach my $suggestion(@$suggestions_loop) {
 
 my $patron_reason_loop = GetAuthorisedValues("OPAC_SUG");
 
-# Is the person allowed to choose their branch
-if ( C4::Context->preference("AllowPurchaseSuggestionBranchChoice") ) {
-    my $branchcode = $input->param('branchcode') || q{};
-
-    if ( !$branchcode
-        && C4::Context->userenv
-        && C4::Context->userenv->{branch} )
-    {
-        $branchcode = C4::Context->userenv->{branch};
-    }
-
-    $template->param( branchcode => $branchcode );
-}
-
 my @mandatoryfields;
 {
     last unless ($op eq 'add');

t/db_dependent/UsageStats.t

@@ -527,7 +527,6 @@ sub mocking_systempreferences_to_a_set_value {
         ShowReviewerPhoto
         SocialNetworks
         suggestion
-        AllowPurchaseSuggestionBranchChoice
         OpacAllowPublicListCreation
         OpacAllowSharingPrivateLists
         OpacRenewalAllowed