Add detail page view for character with list of adventures, character played

[ivellios]

We would like to add character detail page. The page should list all character stats - including extra notes from the player (this was not displayed anywhere yet).

Additionally, we would like to display there a list of the game sessions the character has played in. It should be displayed as a list of adventures in the order of playing (based on the game session dates) with links to the game session detail pages.

Blocked by: dnd-al-krk/portal_backend#15