Update Stop Work funcitonality

**User Story:**
As a contirbutor
I want stop work to be more clear as a feature
So that i know when the right time to click it is

**Acceptance Criteria**
**Remove stop work after work submission**
GIVEN I am a contributor
AND i have submitted work to a bounty
WHEN I view the details page for the bounty that i submitted work to
THEN I should not see the stop work button displayed on the bounties detail page

**Rename Stop work button:**
GIVEN i have applied to work on a bounty (step prior to submitting work)
WHEN i view the bounties detail page referenced above
THEN the stop work button label should be renamed to "Quit Bounty"