Add overview about past rolls, with a basic graphical overview

[Sirs0ri]

Since this BEX is supposed to do all the rolls for a player, it can be used to also to collect the results from those rolls and show the player an overview of:

• [x] how many rolls happened in total
• [ ] which talents were the most rolled
• [x] which attributes were the most used
• [x] some basic stats about success/failure chances
• [ ] create long-term stats about how well r20's RNG is (is there an even 5% chance to roll each side on a d20? are there "good dice" and "bad dice"?)

Additional improvements through:

• [ ] Filtering by time/adventure
• [x] Filtering by character
• [ ] search for talents/attributes

[Sirs0ri]

Basic version implemented in 9796f68c22c0910c48c3cd0be14fa8ee81dc838b

[Sirs0ri]

Filtering by character added in 3cdba8e8d806055056b0751d6ce9c85bb118caf5