Feature Request - Increase Secrets limit on Starter plan

[c9mb]

Issue description

These days almost all external services and APIs that people want to embed or integrate require storing and passing of secrets.

So. the Portal's Secrets feature is a move to making Umbraco sites more secure, and in today's environment, this is a strong point for selling Umbraco to a client vs. their natural inclination to use alternatives - e.g. wpEngine-WordPress is far cheaper.

However... the Starter plan's limit of 5 secrets? - seriously?

Forcing people to pay 6-times as much to get UNLIMITED secrets, is a weird next level in plan features, which none of my clients would opt for, just to get better security.

At EU0.029/10,000 transactions, I can't imagine it costing much to be a bit more generous with the number of secrets on the Starter plan, and reduce the need to store such things in config transformations.