add scope checking for DELETE endpoint for user (deleteUser)

[aryang13]

Acceptance Criteria

• use the middleware function created from this issue: Create Scope and Role Handler Middleware #38
• add the middleware function to call

new LambdaBuilder(router)
    .use(new ScopeController(db))
    .build();

• different scopes should be able to complete different tasks

Development tasks

• work in file: src/roles/deleteUser.ts
• for different scopes add the handling needed

Learning Opportunities

• adding on top of an pre-existing HTTP method