feat: rate modifiers and rules

[xdaluca]

For implementing this, we require:

• Data schema to store the rate modifiers and rules win-stays#99
• Implementation of rules logic (SearchService) #45
• Implementation of rate modifiers (QuoteService) #46

[mfw78]

Thinking about rate modifiers / rules etc:

Order of precedence:

1. Daily override for space.
2. Space default
3. Daily override for accommodation provider.
4. Accommodation provider default (if applicable).

For example:
Space: Student's ski dorm
Space daily overrides:

• Friday and Saturday have a daily surcharge of 10%
  Space default settings:
• Base rate: 30
• Additional adult above 2: 10
  Accommodation facility daily overrides:
• If checkIn day is a Friday, minimum stay of 2 nights.
  Accommodation facility default settings:
• Management Fee of 1% - paid to their property managers, as an example fee
  Accommodation facility tax settings:
• VAT rate of 18%

Alice books the Student's ski dorm checking in on a Friday, and departing the following Friday, for her and 2 other friends therefore she would pay:

1. Friday: (10 + 30) * 1.1 = 44
2. Saturday: (10 + 30) * 1.1 = 44
3. Sunday: (10 + 30)
4. Monday: (10 + 30)
5. Tuesday: (10 + 30)
6. Wednesday: (10 + 30)
7. Thursday: (10 + 30)
   Total: 288 * 1.01 * 1.18 = 343.24 (room rates + management fee + vat)

[mfw78]

This is complete, with the exception of the tax information. As we take that all the prices quoted are going to be inclusive of all applicable taxes (excluding those that are levied at the point of arrival) - then any tax information here would be for 'guidance' / transparency purposes, which is more of a question for the stays-models (ie. Facility metadata).