List all Candidates

### Feature: List all Candidates
>List all candidates in a database.
#### Pre-requisites:
- [ ] complete create Candidate feature
- [ ] candidate table
- [ ] Candidate DAO( list All Candidates )
- [ ] Candidate service ( list All ( ) )

#### Flow:

```mermaid

graph TD;

A[Candidates Service: List of Candidates] --> B[Form Validation]

B -- Yes --> C[Business Validation]
B -- No --> G[Throws Exception]

C -- Yes --> D[Candidates DAO: List of Candidates]
C -- No --> F[Candidates Service: Candidates Not Found]

D --> E[Candidates Service: List of Candidates]

```

Start by checking the Candidate table and the Candidate DAO and service entries named in the prerequisites. Trace the listed flow from form validation through business validation to the DAO, including the not-found path. Done means the create Candidate feature and prerequisites are complete and the service can list all stored candidates.

Written by the indexing model from the issue text.