Creates some reusable helper functions and adds remote realms to
the search results that are checked, which gives coverage for the
remote realm user counts in the support view.
Also fixes formatting for per license price and moves the billing
schedule to be above this line so that it's clearer the per license
price is based on the billing schedule.
Adds a helper since there are only a few different parameters for
all BillingSession child clases, `build_support_url`.
Also, renames `get_support_url` to more explicitly note that it
is for realms: `get_realm_support_url`.
Moves the section in support views for any current plan details
to a new template: `templates/analytics/current_plan_details.html`.
Also, updates the PlanData dataclass to have a boolean that checks
if the current plan tier is the self-hosted legacy plan.
Creates a process_support_view_request method for BillingSession
to process the various support requests that relate to the billing
system.
Moves approve_realm_sponsorship, update_realm_sponsorship_status,
and attach_discount_to_realm to this new BillingSession method.
Adds a new abstract property to BillingSession to have a string
value, billing_entity_display_name, to use for support messages
sent when these requests are processed.
The "send_invoice" and "charge_automatically" strings used by stripe
for the `collection_method` are referred to both as the "billing
method" and "billing modality" in the billing code.
Because we send this as data to stripe as either `collection_method`
or `billing_modality`, renames any references that are any form of
"billing method".
Moves and generalizes `switch_realm_from_standard_to_plus_plan`
in stripe.py to be a more general function for changing a
CustomerPlan to a new and valid tier, `do_change_plan_to_new_tier`.
Adds a helper function with the previous function name to be used
for the support view and management command for changing a realm
from the Standard plan tier to the Plus plan tier.
Moves `update_billing_method_of_current_plan` to the BillingSession
abstract class.
Adds a helper function for support views for the realm case:
`update_realm_billing_method`.
Moves `update_sponsorship_status` to BillingSession abstract class
as `update_customer_sponsorship_status`.
Updates the support views to have a helper for updating this on a
realm: `update_realm_sponsorship_status`.
Makes `approve_sponshorship` an abstract method in BillingSession
abstract base class and moves the implementation for realms to the
RealmBillingSession child class.
Adds `approve_realm_sponsorship` helper function that's used in
the support view and initiates the billing session.
This moves the logic for `attach_realm_discount`, which is used in
the support view, to be in the BillingSession class.
Updates the function name to be `attach_discount_to_customer` so
that the context is generalized vs realm specific.
Updates RealmBillingSession implementation to account for actions
that are initiated by a support admin user.
Also moves the helper function `get_discount_for_realm` that is
only used in support views to `corporate/lib/support.py`.
