Where Do Your Tax Dollars Go – BC

Now that we have BC Spends, we can update [Where Your Tax Dollars Go](https://canadaspends.com/en/tax-visualizer) with BC.

Specifically:
* Add BC as an option in the `Province/Territory` dropdown
* Update copy below it to just say `More provinces coming soon`
* If a user selects BC in the dropdown, the visualizer should update with its provincial spending. Specifically need to figure out:
* Income tax rates for BC, including basic personal amount deduction
* What the provincial spending categories are, and what percentage of spend goes to each category. Provincial ministries may not be called the same as federal, but reasonable assumptions should be made to consolidate those with similar mandates (e.g. how Health was combined together).
* `Transfers to Provinces` amount needs to be updated with the amount transferred to BC ([related](https://github.com/BuildCanada/CanadaSpends/issues/137))
* Add BC's tax bracket as a table to the "Ontario Provincial and Federal tax brackets" section. Update copy accordingly.

Start with the Where Your Tax Dollars Go visualizer and the existing BC Spends implementation, then review issue #137 for the provincial transfer amount. Map the Province/Territory dropdown, spending categories, tax rates, and tax-bracket tables before changing the BC display. Done means BC can be selected, its spending and tax data appear, the copy is updated, and the Ontario section includes BC brackets.

Written by the indexing model from the issue text.