Fix timeframe issue when get SLOs

[nkitanov]

slos.get was is not having time_frame param, so it was always returning the default SLO timeframe. Added it the same way as it is done for slos.list.

[dynatrace-cla-bot]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.

---

Nikolay Kitanov seems not to be a GitHub user. You need a GitHub account to be able to sign the CLA. If you have already a GitHub account, please add the email address used for this commit to your account.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[sonarqubecloud[bot]]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

No Coverage information
No Duplication information

[nkitanov]

I signed the CLA, but still pending.