EDUCATOR-1266

ED-801 Certificate issued date should display the certificate availability date for instructor paced coursest

2. Add site configuration overrides to theming/helpers.py
3. Move microsite.get_value from theming/helpers to site_configuration/helpers
4. Move microsite_configuration.microsite.get_value usages to site_configuration.helpers.values

ECOM-4199

remove CertificateStatuses.regenerating

changes after feedback from matte

Two new certificate statuses are introduced, 'audit_passing' and
'audit_notpassing'. These signal that the GeneratedCertificate is not
to be displayed as a cert to the user, and that they either passed or
did not. This allows us to retain existing grading logic, as well as
maintaining correctness in analytics and reporting.

Ineligible certificates are hidden by using the
`eligible_certificates` manager on GeneratedCertificate. Some places
in the coe (largely reporting, analytics, and management commands) use
the default `objects` manager, since they need access to all
certificates.

ECOM-3040
ECOM-3515

This reverts commit 60860e3a.

An `eligible_for_certificate` field is added to the
GeneratedCertificate model. This way we can retain existing grading
logic, as well as maintaining correctness in analytics and reporting.

Ineligible certificates are hidden by using the
`eligible_certificates` manager on GeneratedCertificate. Some places
in the coe (largely reporting, analytics, and management commands) use
the default `objects` manager, since they need access to all
certificates.

This commit also updates the DB cache for acceptance tests.

Edited text strings in the default template for web certificates to remove wording specific to edx.org. Addresses DOC-2543.

Revert "Edited the text strings in the default template for web certificates to remove wording specific to edx.org"

Edited the text strings in the default template for web certificates. Removed wording that applied specifically to edx.org. Reworded strings so that they will read correctly when the value of platform_name or cert_type requires the a or an article. Addresses DOC-254.

If platform name or "All rights reserved" translation contain non-ascii characters,
certificate HTML view would break with "'ascii' codec can't encode character...".

fixed broken tests and added some optimisations

fixed migration history