Eliminate analytics feature flag

What does this MR do?

This change eliminates the analytics feature flag (not used at all) and ensures that the analytics workspace routes are accessible when at least one analytics feature is turned on.

What was the bug?

We enabled cycle_analytics and productivity_analytics features, but the /analytics route gave us 404, we figured out that there is an additional check for analytics feature in the routes.

Note: docs were updated earlier

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation created/updated or follow-up review issue created
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content