add population UI

[anitanh]

partly fix #57 only the UI

In this PR, the function to fetch population data from database is still not use (commented). I will uncomment those lines when the table is ready.

[lucernae]

Thanks @Ann26 .
Table name conventions are correct.
As for the columns, based on #57
We will have population, females, males, unemployed, elderly.
However since this columns are not disjoint by nature,
If you sum all of it it, it might adds up to more than the total population, so for population tab, let's just disable all total sum counting if it is possible.
We will then think on how's best to show the data.

[anitanh]

oh okay @lucernae or maybe can we have the number of the total population in the summary? so we don't need to sum

[lucernae]

I'm going to merge this to check the UI with local db instance