[Grant] Add New Grant - '04 Plăți si rapoarte'

**About Payments and Reports**
A section describing the deadlines on a Grant, such as when the payments are due or when the sponsor should get a financial report from the CSO.
The Payments are incomes and refer to any sum of money the CSO receives from the source defined under Grant type.
Each grant has a list of expenses (grant budget) that comprise every payment the CSO has made to honor the contract defined in the platform in order to achieve its objectives (budget lines).
The Reports show how each installment was spent, and thus, the incomes & expenses and are building blocks for balance sheets.

**Feature description: user can add the installments as per the contract and generate due-date reports**

Flow:
1. Go to sidebar menu > click on 'Grants', open 'Add grant' page > '04 Plati si rapoarte' [Figma: Plati si rapoarte](https://www.figma.com/file/W7ppl5xGFpB3atVWwYL7qN/Alex-(asistentul-bugetar-al-ONG-urilor)?type=design&node-id=3067-41285&mode=design&t=yED3dImNWgfOJNyS-4)
2. User can add installments to receive as per the contract by clicking 'Adauga o plata' button **_(Figma note to be added as to how this functions)_**
3. User can add report by clicking 'Adauga raport' button **_(Figma note to be added as to how this functions)_**
4. Save
5. Go to next step

**Actions on Payments and reports:**
1. User can add a payment
2. User can add a report
3. User can save the added payment
4. User can save the added report
5. User can go to the next step 05 Documente si note (issue https://github.com/code4romania/alex-api/issues/72)
6. User can go to previous step 03 Bugetul grantului (issue https://github.com/code4romania/alex-api/issues/43)