Task: add support for custom Target roles delegations

[MVrachev]

What is the task about?

We want to add support for custom delegated Target roles.
To achieve this we want to do the following changes inside the bootstrap ceremony:

1. Provide documentation to the user about custom Target roles
2. Ask the user if he wants to use hash bin or custom Target roles delegations

• if he wants to use hash bin delegations continue as usual
• if he wants to use custom target delegation jump to step 3

3. Start a new while: True loop (where at least one role must be added) where the user will be asked:

• enter custom target role name
• enter path prefixes (We need to validate that input of the custom target role paths contains specific characters (letters and numbers for example) DO NOT ALLOW wildcards or . as those can lead to unexpected results.
• enter expiration policy in days
• do you want to add another custom target role?
  • if no, then exit.
  • if yes, then go back to the begging of the loop.

Parent feature

Feature: Create/Remove custom delegate Target Roles

References

• API: Task: add support for custom delegated Target roles at POST /api/v1/bootstrap repository-service-tuf-api#517
• Worker: Task: add support for custom delegated Target roles repository-service-tuf-worker#438

Code of Conduct

• I agree to follow this project's Code of Conduct