Use new show table context helper to merge new and show pages

[prioux]

Now that #771 and #772 has given us the ability to link a set of show table into a single form, we should use this to get rid of all the new.html.erb forms we have and replace them with show.html.erb.

Example:

bourreaux/new.html.erb contains a lot of duplicated comments and inputs when compares to bourreaux/show.html.erb

Views to clean:

• access_profiles
• bourreaux
• custom_filters (? might be tricky)
• data_providers
• groups
• signups
• sites
• tools + tool_configs (? also special)
• users

Issue #754 and PR #755 have already updated each individual show_tables to receive the form builder object.

[prioux]

This is done for ToolConfig and AccessProfile.