Support MSSQL Local Windows Authentication with FQDN-based Certificates

Description: Today the Instana MSSQL sensor in local mode with Windows Authentication validates the server certificate against the machine’s hostname. This fails in environments where SQL Server is configured to issue certificates that contain only the FQDN (for security and compliance reasons).

Additional Details:

Problem:

When the certificate CN/SAN contains only the FQDN, but the Instana MSSQL local sensor uses the short hostname, the TLS handshake fails with a hostname validation error. 

Customers cannot use local Windows Authentication in these environments, even though the Instana agent is running on the same host as SQL Server.

The current workaround is to use remote monitoring and configure each SQL Server instance explicitly with its FQDN. However, this requires large-scale agent configuration changes and is not practical for customers rolling out Observability as a Service across hundreds or thousands of MSSQL instances.

Example: 

Hostname: server01

Domain customer.local

--> FQDN: server01.customer.local

The MSSQL Sensor will only allow authentication for a certificate signed with "server01", not "server01.customer.local".

Request:

Enhance the Instana MSSQL sensor to support FQDN validation for local Windows Authentication connections, so that:

The agent can connect locally with Windows Auth while validating against the FQDN in the certificate.

Customers do not need to switch to remote mode or manage individual MSSQL instance configurations.