Fix downtime and recheck functions for CheckMK 2.3

[jkim2492]

Since the upgrade from version 2.2 to 2.3 of CheckMK, the downtime and recheck commands stopped working from Nagstamon (acknowledge is still working). It seems like CheckMK is trying to deprecate the legacy API in favor of the new REST API.

We haven't been able to pin-point the exact change that caused this incompatibility. However, we were able to find evidences that CheckMK is trying to drop the legacy API in favor of the REST API. Below are some examples of changes that force users to use the REST API:

• Werk #16689: Decommission legacy check API

Commandline call plugins for special agents and active checks in this folder will still work, but we provide a new API for those as well now (see Werk #16259). They will stop working in Checkmk 2.4.

• Werk #13640: Deprecation of Web API

We recommend migrating all existing scripts that use the Web API to the REST API as soon as possible to catch issues early before you move to CheckMK 2.2.

Changes made in this PR have been tested against:

• Legacy CheckMK 1.2.6p12 on Bionic
• OMD CheckMK 2.2.0p26.cre on Focal
• OMD CheckMK 2.3.0p3.cre on Jammy

Contact: [email protected]