Add config value STRIPE_CURRENCY

[amrsoll]

This allows me to change the currency I use in Stripe.

I would also recommend to refactor CURRENCY -> STRIPE_CURRENCY to follow your code conventions.

I kept the changes minimal for this PR so far.

:warning: I presume this would require a migration step, which I am unsure of how to tackle.

[emanuelen5]

LGTM. However, note that there are more places where we need to update the currency.

• E.g. https://github.com/makerspace/makeradmin/blob/df0fb76592e2906385ff5598e0db0f9ce878b4a2/admin/src/Components/ProductForm.jsx#L89 I think a way to insert the currency into the .js files can be like we do for the build date:
• Defining variables in webpack.js: https://github.com/makerspace/makeradmin/blob/df0fb76592e2906385ff5598e0db0f9ce878b4a2/admin/webpack.config.js#L71-L72
• and then using them in the JavaScript file: https://github.com/makerspace/makeradmin/blob/df0fb76592e2906385ff5598e0db0f9ce878b4a2/admin/src/Settings/About.jsx#L17-L21

[emanuelen5]

⚠️ I presume this would require a migration step, which I am unsure of how to tackle.

I don't think we need to add any migration scripts since these values only are used in runtime. Either way, I think it's very low risk that someone started using one currency and then switching to another, and that this change would affect anyone negatively. I don't think we have a lot of users in total, and even fewer outside of Sweden.

[emanuelen5]

a migration step, which I am unsure of how to tackle.

Migrations are done by creating a new file in api/src/migrations/ (with higher starting number than the last file). Currently the last migration is this one: https://github.com/makerspace/makeradmin/blob/master/api/src/migrations/0023_flexible_change_phone_number.sql

The files are executed in-order on the database. They contain SQL commands that alter the database so that it matches the new database format that the code expects.

E.g. the following adds a column called _pendingactivation to the _membershipmembers table with a boolean value.

ALTER TABLE membership_members ADD COLUMN `pending_activation` boolean;

Executed migrations are stored in the database so they are not applied twice.