PPR - Crown Charge Registrations (Registries Staff)- Only 1 Secured Party is allowed in the Registration and Amendment

**Describe the bug in the current situation:**
- When a user enters more than 1 secured party in the Crown charge registrations for the staff, then the UI is not restricted with the validation.
- In the Amendment flow, when the user adds a new Secured party, then the existing secured party should automatically be disabled same as the client account. (Please refer to BCREG0057 account in DEV for the functionality)

**Link bug to the User Story:**

**Impact of this bug:**
Impacts all the crown charge registrations when more than 1 secured party is entered in the staff account.

**Chance of Occurring (high/medium/low/very low):**
High

**Pre Conditions:**
Login to staff account (BRTEST1)

**Steps to Reproduce:**
**Registration Flow**
- Navigate to the PPR Registration table
- Select a Crown charge registration/Other registrations from the list
- Navigate to 'Add Secured Parties and Debtors' (step2)
- Enter more than 1 secured party by the code or manually
- User is not restricted in adding the secured party with validation.

**Amendment Flow:**
- Complete a Crown charge registration by adding 1 secured party.
- Navigate to the PPR table and select the crown charge registration to file an Amendment
- Navigate to the secured party step and add a new secured party by the code or manually
- The existing secured party should be disabled automatically when a new one is added to the table, currently it is not.

**Expected behavior:**
When the user adds a second secured party to the table, then the 'Change Secured Party' modal should be presented and user can choose to add by clicking on the 'Change Secured Party' button which replaces the existing one and by clicking on the 'Cancel' button will cancel the newly selected/entered secured party.

Amendment:

**Screenshots/ Visual Reference/ Source:**