LEARNER-6946 management command to send verification expiry email

Template for email added (email/verification_expiry_email)
The management command filters the SoftwareSecurePhotoVerification model on the basis of following criteria :
-- the verification is approved
-- the start_date < expiry_date < today or specified days have passed to resend email
After the basic filtering batches are created to send email. For each verification in a batch email is sent and email_expiry_date is set to 15 days from today (default days are 15, it can be changed too)
Between each batch there is a delay of sleep_time seconds

Template for email added (email/verification_expiry_email)
The management command filters the SoftwareSecurePhotoVerification model on the basis of following criteria :
-- the verification is approved
-- the start_date < expiry_date < today or specified days have passed to resend email
After the basic filtering batches are created to send email. For each verification in a batch email is sent and
email_expiry_date is set to 15 days from today (default days are 15, it can be changed too)
Between each batch there is a delay of sleep_time seconds

Improve 403 error handling

LEARNER-7136 populate expiry date and add mechanism for new verification

Method approve() is overridden to accommodate new users that will have their verification approved in the future. The approve() method is called from software secure results callback every time a Software Secure Photo Verification is approved.The method overridden now updates expiry_date and then calls super to perform task it was performing before this change.The expiry_date set is the same as the one sent in verification approval email.

In results_callback for sspv the expiry_date and expiry_email_date for the most recent previous verification if exists are also updated to NULL.

ARCH-472: Add user_id for username in event data.

In certain use cases, a caller may have the username and not the
user_id. In these cases, we add the user_id since events have
standardized on using the user_id as the unique id of a user.

ARCH-472

allow configurability of the minimum price for a course mode

Delete flaky bokchoy tests.

EDUCATOR-4164, EDUCATOR-4165, EDUCATOR-4166

Merge pull request #19937 from edx/matthugs/shore-up-whitespace-on-proctoring-instructions-page-for-PSI-exams

Shore up whitespace on proctoring instructions page for PSI exams

REVMI-95: Cale/fbe access expiry reminder

JIRA:EDUCATOR-4105

Add price information to enrollments and create dashboard_metadata

Remove one-off management commands to rehash retired emails/usernames

Currently, ajax calls in courseware is handling 403 like 401.
In this PR, proper modifications have been done to make it
coherent with its intended behaviour.

LEARNER-7131

remove flaky bokchoy test

REVEM-219 Get program info even if user isn't yet enrolled in the course

Caching full response

Fix Incorrect data for cert table

Method approve() is overridden to accommodate new users that will have their verification approved in the future.
The approve() method is called from software secure results callback every time a Software Secure Photo Verification
is approved.The method overridden now updates expiry_date and then calls super to perform task it was performing
before this change.The expiry_date set is the same as the one sent in verification approval email.

In results_callback for sspv the expiry_date and expiry_email_date for the most recent previous verification if exists
are also updated to NULL.

cache full response regardless
of fields given or not. Reason
for doing this to avoid cache
overridden. For some courses
get_user_course_expiration_date
was overriding certificate template
cache in render_html_view

Learner-6943

EDUCATOR-4128

REVMI-93 stop ignoring enrollment creation date if the user is masquerading

for experiments.

REVEM-174

PLAT-2288

Use single yaml config instead of two json configs.

Inserting JSON string into Vertica instead of JSON obj

This reverts commit 8c805999.

[REVMI-108] stop bucketing new users into FBE holdback