Make organization title configureable

Problem/Motivation

Rendering issue credits through the block plugin system should use the organization title from config settings.

Steps to reproduce

• Add an organization id in the admin config form.
• Place the block using block layout.
• Note that the organization title from config is not rendered in the block.

Proposed resolution

Set a variable in ContributionCreditApi class to pull in the organization's title to be displayed in the block.