Membership section label mixup

Summary
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Currently when initially configuring a simple (quick config) online membership sign and renewal form (Online Contribution page : Memberships tab), we automagically set the hidden (quick config) price field label for the membership_types radio button to the either the value the user enters for the New Membership Title, OR to a default string ('Membership') if the user leaves that title field empty.

(see line 393 in CRM_Member_Form_MembershipBlock)

Once the membership block is created, there is no way to modify that field label, AND the title may often not be an appropriate label for the radio button field.

We should expose that value to the user when creating (and editing) the membership block.

Implementation
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Add a form field to the membership block form:

• label = 'Membership Types Label'
• place this field above the Membership Types table

SetDefaults: New block default value = 'Membership'. If editing an existing membership block, grab the linked price_field.label value to set default for the new form field.

PostProcess: When creating or editing the membership block, use the value from this form field to set the price_field.label for the associated price field.

== Original Post ==========
I also tested this on the wordpress demo site and the see the bug there. I was only able to test as membership renewal test page, but the bug is still there.

Steps (Wordpress 4):

1. add a contribution page, set it up as a membership sign up.
2. enter the title text on the membership tab and save
3. go to either the live or test page
4. see that the title text appears next to my membership type radio buttons (why? Text should say Membership Type.)
5. reenter the contribution page editor membership tab
6. edit that title text to something else, save
7. go back to either the live page or test page
8. see that the newly edited title text appears in a different place, the title of the section
9. see that the original title text remains next to the radio buttons
10. the original text can't be edited, since the edit page for an existing page puts the text in a different location.

I think that the new page edit code and the code for modifying an existing page have this title feature mixed up.