## Description
This PR adds to the `estimate_billing` option to the `appsmithctl` command. This will help existing users estimate their bill when they consider upgrading to the paid edition.
Usage:
```
appsmithctl estimate_billing
Options:
--sessionPrice The price per active session. Defaults to 0.3
--priceCap The price cap for a user in a given month. Defaults to 15
```
A user can also run the command for various scenarios to determine the optimum capacity tier.
## Type of change
- New feature (non-breaking change which adds functionality)
- This change requires a documentation update
## How Has This Been Tested?
Manually
## Checklist:
- [ ] My code follows the style guidelines of this project
- [x] I have performed a self-review of my own code
- [x] I have commented my code, particularly in hard-to-understand areas
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my feature works
- [ ] New and existing unit tests pass locally with my changes
