[14.0][ADD] contract_invoice_plan, contract_invoice_plan_selection

[kittiu]

Similar to purchase_invoice_plan, sale_invoice_plan

This module add ability for contract to create invoices based on the predefined invoice plan, either all at once, or one by one.

Note: Choosing to use invoice plan on contract, will disable the default recurring invoice feature.

[github-actions[bot]]

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