Expense templates

[maraf]

Some expenses are repeating in time. This will user to create a template that can be applied.

• A list of templates.
• Apply template from template list.
• Selection of template when creating expense.
• Create a template based on selected expense.

Template has not any field required. Template can be named.

Further extension: Scheduled templates. I define a schedule, an expense will be automatically created from template.

• [x] #397 - API (create and delete).
• [x] #417 - Blazor (create, apply and delete).