[TASK] Levelized Cost as an Economic Metric

Issue Description

Is your feature request related to a problem? Please describe. HERON should be able to calculate and report back a levelized cost metric for a given cashflow (or perhaps multiple, though seems rare).

Describe the solution you'd like HERON should be able to communicate with the TEAL NPV_search function. If the target is set to 0, that finds the "multiplier" on the cashflow that makes the NPV sum equal to 0 (i.e., the breakeven price of the resource).

Describe alternatives you've considered

For Change Control Board: Issue Review

This review should occur before any development is performed as a response to this issue.

[ ] 1. Is it tagged with a type: defect or task?
[ ] 2. Is it tagged with a priority: critical, normal or minor?
[ ] 3. If it will impact requirements or requirements tests, is it tagged with requirements?
[ ] 4. If it is a defect, can it cause wrong results for users? If so an email needs to be sent to the users.
[ ] 5. Is a rationale provided? (Such as explaining why the improvement is needed or why current code is wrong.)

For Change Control Board: Issue Closure

This review should occur when the issue is imminently going to be closed.

[x] 1. If the issue is a defect, is the defect fixed?
[x] 2. If the issue is a defect, is the defect tested for in the regression test system? (If not explain why not.)
[x] 3. If the issue can impact users, has an email to the users group been written (the email should specify if the defect impacts stable or master)?
[x] 4. If the issue is a defect, does it impact the latest release branch? If yes, is there any issue tagged with release (create if needed)?
[x] 5. If the issue is being closed without a pull request, has an explanation of why it is being closed been provided?

idaholab / HERON