Add billing tables (#8772)

Beforehand, the name of the branch is not representative of the work
that has been done in this PR

**TLDR:**

Solves https://github.com/twentyhq/private-issues/issues/192
Add 3 tables BillingCustomer, BillingProduct and BillingPrice and
BillingMeter to core, inspired by the Stripe implementation. Separates
migration, between common and billing on order to not populate the db of
the self-hosting instances with unused tables.

**In order to test:**

Run the command:
npx nx typeorm -- migration:run -d
src/database/typeorm/core/core.datasource.ts


**Considerations:**

I only put the information we should use right now in the Billing
module, for instance columns like meter or agreggation formula where
omitted in the creation of the tables.
These columns and other ones who fall on the same spectrum will be added
as we need them.

If you want to add more information to the table, I'll leave some
utility links down bellow:

- BillingPrices: https://docs.stripe.com/api/prices/object
- BillingCustomer: https://docs.stripe.com/api/customers/object
- BillingProduct:  https://docs.stripe.com/api/products/object

**Next Steps**

Use the Stripe Webhook in order to update the tables accordingly

---------

Co-authored-by: Félix Malfait <felix@twenty.com>

packages/twenty-server/src/engine/core-modules/environment/environment-variables.ts

@@ -24,11 +24,11 @@ import { LLMTracingDriver } from 'src/engine/core-modules/llm-tracing/interfaces
 
 import { CacheStorageType } from 'src/engine/core-modules/cache-storage/types/cache-storage-type.enum';
 import { CaptchaDriverType } from 'src/engine/core-modules/captcha/interfaces';
+import { AssertOrWarn } from 'src/engine/core-modules/environment/decorators/assert-or-warn.decorator';
 import { CastToBoolean } from 'src/engine/core-modules/environment/decorators/cast-to-boolean.decorator';
 import { CastToLogLevelArray } from 'src/engine/core-modules/environment/decorators/cast-to-log-level-array.decorator';
 import { CastToPositiveNumber } from 'src/engine/core-modules/environment/decorators/cast-to-positive-number.decorator';
 import { CastToStringArray } from 'src/engine/core-modules/environment/decorators/cast-to-string-array.decorator';
-import { AssertOrWarn } from 'src/engine/core-modules/environment/decorators/assert-or-warn.decorator';
 import { IsAWSRegion } from 'src/engine/core-modules/environment/decorators/is-aws-region.decorator';
 import { IsDuration } from 'src/engine/core-modules/environment/decorators/is-duration.decorator';
 import { IsStrictlyLowerThan } from 'src/engine/core-modules/environment/decorators/is-strictly-lower-than.decorator';