Settings page improvements

[BenMusch]

Two areas from improvement:

1. Add a section grouping, which can either be added like:

high_opp_penalty:
  ...
  section: Pairing algorithm

Or like:

- section: Pairing algorithm
  description: Modify the weights of the pairing algorithm
  settings:
      - high_opp_penalty:
         ...

and then use this to group in the UI to organize things clearly as we add more to the yaml file

2. Add another type: enum (like boolean)

Based on recent doomthreads constructive discussions it seems like there's strong support to at least have the option to pair judges based on a middle-out style, and some other tweaks like this. Though a boolean may make sense in some instances, an enum is probably a better choice so support the possibility of having more than 1 way to pair judges.

The yaml file could look like:

judge_pairing_strategy:
  type: enum
  options:
    - "Middle out"
    - "Top down"
    - "Randomized within bracket"

On the UI, this would lead to a select box where the display is the listed option and the value is the index in the list

Additionally, we could add support for a function on the TabSetting module like:

def coerced_value(self):
  # parse the yaml config based on self.name
  if yaml_config["type"] == "boolean":
    return self.value == 1
  elif yaml_config["type"] == "enum":
    return yaml_config["options"][self.value]
  else:
    return self.value