Fix: correct SCCM config encryption and query handling

[Rom1-B]

Checklist before requesting a review

Please delete options that are not relevant.

• I have performed a self-review of my code.
• I have added tests (when available) that prove my fix is effective or that my feature works.
• I have updated the CHANGELOG with a short functional description of the fix or new feature.
• This change requires a documentation update.

Description

• It fixes #N/A
• Some SCCM configuration fields were stored and displayed in plain text instead of being encrypted like the other credential fields, and the default certificate validation setting was not enabled by default.
• Device identifiers used when building database queries, XML files and file paths were not validated or parameterized, and connection error messages were not escaped before being displayed.
• This fix aligns these fields and code paths with the existing patterns already used elsewhere in the plugin.

Screenshots (if appropriate):