feat: expose DD RUM sessionSampleRate and sessionReplaySampleRate

[secustor]

Hey, I just made a Pull Request!

This PR allows to set sessionSampleRate and sessionReplaySampleRate via config API

:heavy_check_mark: Checklist

• [x] A changeset describing the change and affected packages. (more info)
• [x] Added or updated documentation
• [ ] Tests for new functionality and regression tests for bug fixes
• [ ] Screenshots attached (for UI changes)
• [x] All your commits have a Signed-off-by line in the message. (more info)

[backstage-goalie[bot]]

Missing Changesets

The following package(s) are changed by this PR but do not have a changeset:

• @backstage/cli

See CONTRIBUTING.md for more information about how to add changesets.

Changed Packages

Package Name	Package Path	Changeset Bump	Current Version
example-app-next	packages/app-next	none	v0.0.11-next.0
example-app	packages/app	none	v0.2.97-next.0
@backstage/cli	packages/cli	none	v0.26.5-next.0

[github-actions[bot]]

Uffizzi Cluster pr-24564 was deleted.