Delete flight

### Feature: delete flight

#### Pre-requisites:
- [ ] Complete create flight feature
- [ ] Flight DAO( delete Flight )
- [ ] Flight service ( delete (String flightNo ) )
#### Validations:
- [ ] Form Validation
* delete ( Flight flight )
* flightNo(null, empty)
- [ ] Business Validation
* check the flight Already exists
#### Messages:
* Invalid flightNo input
* flight not exists
#### Flow:
```mermaid
graph TD;

A[Value Passed to Flightservice - flight Object] --> B[Form Validation]
B-->C[ Business Validation]

C--> D{Validation Result}

D -- Valid --> E[Value Passed to flightDAO]

E --> F[update active status in Database]

D -- Invalid --> G[Validation Exception]
```