For consistency with other assets like OS and Hosts, TLS Certificates
always deleted completely with delete_tls_certificate.

This adds sha256_fingerprint and serial as table columns and params for
get_certificate_info and also adds an incomplete migrator that drops the
now unused tls_certificates_trash table and adds the new columns.

The migrator will fail intentionally in this commit because more columns
are to be added in following commits.

…e-assets

…e-assets

This can be used to get certificate data from "SSLDetails" host details.

This avoids possible issues with unitialized memory.
Also the default certificate_format return has been clarified.

This makes it more consistent with the other certificate helper
functions that do not perform any database operations.

…e-assets

The SHA-256 fingerprint is used by OpenVAS to identify certificates,
the serial is also collected by the scanner and the source data
can be used to associate certificates with certain hosts and reports.

The clause was missing in the create_tables() function.

The get_tls_certificates command will now contain sha256_fingerprint
and serial elements.

TLS certificates use bigint because some expiry times may not fit into
the limits of the integer type.

This gives the most recent time the certificate was found in a scan or
imported.

When details are requested, get_tls_certificates command will now return
a list of sources giving the locations (hosts and ports) and origins
(e.g. reports) where a certificate was found.

The TLS certificate assets are meant to represent the actual certificate
contents and replacing them with a different certificate would lead to
incosistencies like no longer matching a certificate as found in a scan.

The GMP commands create_tls_certificate and delete_tls_certificate now
create/delete sources, locations and origins of the certificate.

A TLS certificate is considered a duplicate if the current user has one
with the same fingerprint but copying from other users is still allowed.

The copy_tls_certificate function was missing these columns.

The creation of the TLS certificate from Base64 encoded certificate data
has been moved from create_tls_certificate to a new function that
can be reused in other contexts like host details.

…e-assets

This separates the insertion of the tls_certificates row from getting
the data from a Base64 encoded certificate.

The make_tls_certificate and user_tls_certificate_match_internal
functions now quote the given certificate data because DNs can contain
single quotes and other fields could contain other arbitrary text.

This adds documentation of the return value of make_tls_certificate
and make_tls_certificate_214.

Every time the scan of a host has finished, the collected host details
will be used to create TLS certificate assets or amend them with new
source information.

…e-assets

This removes some leftover test output, frees the decoded certificate
content in add_tls_certificates_from_report_host and adds checks if
make_tls_certificate was successful, also ensuring tls_certificate is
defined.

The functions have been moved from src/manage.c to the new file
manage_tls_certificates.c.

- Placing of the comma and inline comments is made more consistent.
- Declaration and initialization of variables is separated in
 migrate_213_to_214.
- Comments have been added to explain the iterators in the migrator.

The summary of the copy element had a superflous period.