Add functionality to insert a secert

[mkah91]

Description

As a user I want to be able to use the cli for inserting a new secret in the keyvault.

Idea

Multiple queries to the user:

> azkv insert my-new-secret
Enter the value for my-new-secret: 
> abcd1234
Enter the description for my-new-secret:
> This is a secret
Enter the expiration date for my-new-secret:
> 2020-01-01
Enter the tags for my-new-secret:
> tag1=a,tag2=a

For non interactive each value can be also provided by option

azkv insert my-new-secret --value abcd1234 --description "This is a secret" --expiration 2020-01-01 --tags "tag1=a,tag2=a"

As soon as options are provided there will be no more queries to the user, besides you provide e.g. --full which will end up in querying the user for inputs not yet provided by options.

AC

• The user is able to insert secrets into a keyvault using the azure cli
• The user is able to pass the name of the secret
• The user is ablte to pass the value of the secret
• The user is able to provide the expiration of the secret
• Invalid expiration input is throwing an error
• Inserting a secret requires at least a name and a value, if those values are not provided this leads to a error

Maybe

• The user is able to pass the description of the secret
• The user is able to provide tags of the secret