Additional Placeholders for Level Calculation

[NFRCG]

Description

Is your feature request related to a problem?

No

Describe the solution you'd like us to implement.

I would like for additional values/placeholders for the level calculation section of the config to be implemented so that you could have access to the following info when calculating Island Level:

1. Total Amount of All Blocks - This would be a count of all blocks included within the island space. This number is currently printed out when calculating level from console. This could either include air blocks, or not include air blocks via a configuration option or separate placeholders
2. Total Amount of Current Block - This would be a total amount of the block whose value is currently being calculated.

Describe alternatives you've considered.

There are not too many alternatives. The level calculation section only currently accept block value and level cost as acceptable values at the moment, from what I can see?

Additional context

The main reason for this request is so that there can be even more freedom in how servers calculate their island level for users.

add more placeholder like :
the number of stone blocks placed on the island for example to be able to add them to the calculation of levels.
It would allow us to make a formula if you put too many times the same blocks it pays less ^^