Performance improvement when creating the model

[GregoryWullimann]

• Refactored some part of the model creation. Mostly reduced the number of iteration over the player dataset.
• Added a wrapper function to log the execution time, useful for keeping track of slow part methods. Logging can be enabled/disabled changing LOG_RUNTIME in input.py
• Added requirements.txt so it's easier to install dependencies
• Converted XSLS to CSV to improve data reading performance

Model creation now takes about 10 seconds to create. create_basic_constraints is the slowest function now and can be definitely improved.

Processing time create_var: 0.11 seconds
Processing time create_basic_constraints: 7.37 seconds
Processing time create_max_club_constraint: 0.29 seconds
Processing time create_unique_league_constraint: 0.11 seconds
Processing time create_min_country_constraint: 0.22 seconds
Processing time create_rarity_2_constraint: 0.03 seconds
Processing time create_chemistry_constraint: 3.38 seconds

[Regista6]

Extended your code. Here's what I got:

Processing time create_var: 1.06 seconds
Processing time create_basic_constraints: 0.33 seconds
Processing time create_max_club_constraint: 0.05 seconds
Processing time create_unique_league_constraint: 0.08 seconds
Processing time create_min_country_constraint: 0.08 seconds
Processing time create_rarity_2_constraint: 0.02 seconds
Processing time create_chemistry_constraint: 2.89 seconds

Need to do some testing with different inputs. Thanks very much!

[Regista6]

Additionally tested on:
https://www.futbin.com/squad-building-challenges/EXPIRED/250/tsg-hoffenheim-v-bayern-munchen (with solver.parameters.random_seed = 42),
https://www.futbin.com/squad-building-challenges/ALL/27/fiendish (with df = df[df["ID"] <= 1000]),
https://www.futbin.com/squad-building-challenges/ALL/28/puzzle-master (with df = df[df["ID"] <= 1000]),
https://www.futbin.com/squad-building-challenges/ADVANCED/19/the-whole-nine-yards (with all players from Brazil constraint) and
https://www.futbin.com/squad-building-challenges/ADVANCED/17/Give%20Me%20Five

Seems to work !.