Fix copy in Issue Tracker empty state

What does this MR do?

Fix and tweak copy in the Issue Tracker empty state. Some specifics:

• Replace “todo” with “tasks” to avoid confusion with the Todos feature
• Be simpler and more concise
• Avoid exclamation points
• Omit punctuation after phrases and labels to create a cleaner and more readable interface. Only for consecutive sentences in paragraphs.

Screenshots (if relevant)

Before	After

Does this MR meet the acceptance criteria?

• Changelog entry added
• Conform by the style guides
• Branch has no merge conflicts with master (if it does - rebase it please)

What are the relevant issue numbers?

None