Add new CAPEX Constraint Inputs

[adfarth]

Add Financial inputs: min_initial_capital_costs_before_incentives and max_initial_capital_costs_before_incentives
Add CHP output: initial_capital_costs
Aligns with REopt.jl PR: NREL/REopt.jl#491

[zolanaj]

Looks good, thank you @adfarth! I made one comment paired with implementing the recommended change. If tests pass I think this is good to merge!

[Bill-Becker]

@adfarth @zolanaj I'd like to make sure we're not going to make CHP run very slowly before we merge this, especially for the web tool (but also concerned about the recently-merged REopt.jl too).

[adfarth]

@adfarth @zolanaj I'd like to make sure we're not going to make CHP run very slowly before we merge this, especially for the web tool (but also concerned about the recently-merged REopt.jl too).

noting here that this is no longer a concern

[Bill-Becker]

@zolanaj @adfarth I had to merge this branch in with my other branch in the PR:
#644
So I think this PR will automatically close when I merge that PR next week. Based on the status of this PR, seems like it's good to go anyway. Just letting you know about that.