fix(dynamic-sampling): add option for switching bw spans and transactions (v2)

[shellmayr]

• Use an option with a list of orgs instead of feature flags because it's faster
• Should be in-memory and therefore significantly faster than feature flags
• We can do this because we do not expect large quantities of orgs to be added to this
• Previous batch-checking solution had high performance penalty despite multiple optimizations

Reapplies #102576 - the metrics didn't look good in the beginning, so I reverted, but afterwards everything seemed to work fine, so I think we can apply it after all

Contributes to TET-1147

[linear]

TET-1147 Verify Functionality of Dynamic Sampling on AM3