Update Program Activities headers, labels, and help text

[beparticular]

In our recent conversation with the state of ID, it was noted that it was hard to find where to click to add the activities. We've also noticed that in navigating the app, there's always a hesitation in clicking when looking for the Activities section and sometimes a misclick on Activity Schedule Summary bc it starts with Activities. We've heard this before and considered changing things, but had never prioritized the work. It seems like these small changes could make a big impact upon release.

Builder View

Export View

(We already ran this by Caryn offline, so putting in for dev prioritizing)

This task is done when...

• "Program Activities" header is changed to "Activities"
• The redundant "Program Activities" header with the number of Activities before it is removed
• The help text under the Activities Header is changed to "Activities are narrowly scoped bodies of work that comprise the APD. This section will help you explain the goals, timelines, scope, and costs of each activity."
• "Program Activities" is changed in the nav to "Activities"
• "Activity List" in the sub nav is changed to "Add Activity"
• Export view remains mostly the same, but the number on the header is removed along with the word "Program"