feat: SDKE-852 add joint sdk select placements timestamp

[khushi1033]

Background

• Added support for the jointSdkSelectPlacements timestamp to increase coverage to timing data collected by the Joint SDK

What Has Changed

• Added jointSdkSelectPlacements timestamp to be captured when selectPlacements is called by RoktManager

Screenshots/Video

• N/A

Checklist

• I have performed a self-review of my own code.
• I have made corresponding changes to the documentation.
• I have added tests that prove my fix is effective or that my feature works.
• I have tested this locally.

Additional Notes

• N/A

Reference Issue (For employees only. Ignore if you are an outside contributor)

• Closes https://rokt.atlassian.net/browse/SDKE-852

[sonarqubecloud]

Quality Gate failed

Failed conditions
29.7% Duplication on New Code (required ≤ 3%)

See analysis details on SonarQube Cloud