Task/#256 add statistics details

[OldMetalmind]

Closes #256

Description
Adds plot regarding Confirmed Cases, Deaths, Recovered and Hospitalized information of the current status of Covid19 in Portugal. It is possible to filter by day.

Important Note for testers
The library used for ploting was fl_flutter (https://pub.dev/packages/fl_chart) and given its limitation not every feature was able to be implemented, before opening an issue please contact me @OldMetalmind .

Not implemented

• Logarithmic scales
• "Ticks" for the vertical lines for he x axis days
• HospitalizedUCI cases proportion not showing in between backgrounds in the plot
• Horizontal Bar plots

Notes

• Given the amount of new files and changes, it would be preferable to have two reviews before merging
• After this merge, we need to create more tasks for not implemented features and find a better solution for the plots and its limitations.
• There is a lot of room for improvements and code optimizations.

Changes

• Added new screens for each of the types of plots details
• Navigation from the updated Statistics overview
• Loading the data from the Splash screen

Required to run
This is running to against the local running Docker container, you will need to set it up on your machine or se the production build to test.

https://github.com/dssg-pt/covid19pt-data

[Vanethos]

Can you please add screenshots? :D

[miguelpruivo]

I have to take a whole day to review this! 😄

[Vanethos]

Overall.. AMAZING work! Pro moves detected!!!

Only a few minor things, including a missing license and commented code

[miguelpruivo]

Overall, like @Vanethos said, it looks great and there's an incredible amount of work here. Congrats! 🎉

Other than minor things that I added to @Vanethos suggestions, it looks ok to me as well. I would only run flutter format . on the project just to make sure all files are formatted accordingly.

[danidroid]

Amazing work @OldMetalmind
just found some small things on UI while running on smaller devices and some imports out of place above license