Better HTML titles

### Is your feature request related to a problem?

The Flagsmith frontend always has the same HTML ``. This makes it impossible to find things by searching or autocompleting browser history:

<img width="517" alt="Image" src="https://github.com/user-attachments/assets/7b13feb8-a40b-4411-8a3a-f995514410c7" />

Compare this to how GitHub uses titles:

<img width="522" alt="Image" src="https://github.com/user-attachments/assets/5910a520-aab7-4b80-acdd-21d82149dd62" />

Or our docs:

<img width="509" alt="Image" src="https://github.com/user-attachments/assets/177ee97e-ea89-453b-bdb7-221474b05974" />

### Describe the solution you'd like.

Have nice, short titles on as many Flagsmith pages/resources/sections/etc as we can.

### Describe alternatives you've considered

I also think the frontend should not have the tagline after "Flagsmith" in the title. That makes sense to have in the marketing website where we're introducing and explaining Flagsmith, but not in the frontend where it's just the name of the application being used.

### Additional context

_No response_