UHF-7484: Add initial version of service housing service voucher calculator

[Arkkimaagi]

UHF-7484

• Adds support for service housing service voucher calcultor

What was done

• New calculator

How to install

• Make sure your instance is up and running on latest dev branch.

  • git pull origin dev
  • make fresh

• Update the HDBT theme

  • composer require drupal/hdbt:dev-UHF-7484_service_housing_service_voucher

• Enable calculator module in console: drush en helfi_calculator

• Add calculator paragraph to upper and lower content area in /admin/structure/types/manage/page/fields

• Enable "Service housing service voucher"-calculator from /admin/tools/calculator-settings and add Calculator data from below:
  

CLICK ME! Calculator data for Service housing service voucher

Calculator data for "Service housing service voucher"

{
  "voucher_from_net_income": {
    "0": 3300,
    "900.01": 3200,
    "1000.01": 3100,
    "1100.01": 3000,
    "1200.01": 2900,
    "1300.01": 2800,
    "1400.01": 2700,
    "1500.01": 2600,
    "1600.01": 2500,
    "1700.01": 2400,
    "1800.01": 2300,
    "1900.01": 2200,
    "2000.01": 2100,
    "2100.01": 2000,
    "2200.01": 1900,
    "2300.01": 1800,
    "2400.01": 1700,
    "2500.01": 1600,
    "2600.01": 1500,
    "2700.01": 1400,
    "2800.01": 1300,
    "2900.01": 1200,
    "3000.01": 1100,
    "3100.01": 1000,
    "3200.01": 900,
    "3300.01": 800,
    "3400.01": 700,
    "3500.01": 600
  }
}

How to test

• Check that the calculator works (numbers can be entered, result can be seen)
• Check that code follows our standards

Designers review

• This PR does not need designers review

[Jussiles]

Works as expected as code looks good. Added couple of comments to consider and one typo to fix.