Automate subscriptions

[rgoj]

It'd be great to finally automate subscriptions.

At the very least, it'd be nice to send the organisation ID from Maptio to chargebee to make it easier to identify the organisation when we create manual subscriptions.

Creating this issue now as it just caused a problem - I mistakenly assigned a subscription manually to an incorrect organisation, see more here: https://github.com/Maptio/maptio/issues/831#issuecomment-1840119049

[rgoj]

The lack of this functionality has caused some pain again:

• https://app.intercom.com/a/inbox/q3x5lnhp/inbox/conversation/106323200018998
• https://app.intercom.com/a/apps/q3x5lnhp/users/6655d0c1ad508aa7722dabcf/all-conversations

In the latter case, I couldn't activate the subscription immediately as my broadband was temporarily down (that problem should be addressed now as I now, after yesterday's issues, have a better backup, yay - in general though there are many circumstances in which this could happen again).

[rgoj]

Here is another case of a missed subscription that came in overnight due to time zone differences and I'm worried might have potentially caused issues for the organisation: https://app.intercom.com/a/inbox/q3x5lnhp/inbox/conversation/106323200019284

[rgoj]

Another subscription that came in while I was asleep and had my notifications turned off, resulting in an unpleasant experience for a user (who still wrote a gracious email!): https://app.intercom.com/a/apps/q3x5lnhp/conversations/106323200019611