Add survey design support to StaggeredTripleDifference #698

Job	Run time
Pure Python Fallback	53m 34s
Rust Unit Tests (ubuntu-24.04-arm)	1m 22s
Rust Unit Tests (macos-latest)	1m 30s
Python Tests (ubuntu-24.04-arm, py3.13)	18m 46s
Rust Unit Tests (windows-latest)	2m 21s
Python Tests (ubuntu-latest, py3.13)	40m 16s
Python Tests (ubuntu-latest, py3.11)	40m 20s
Rust Unit Tests (ubuntu-latest)	1m 32s
Python Tests (windows-latest, py3.11)	37m 56s
Python Tests (macos-latest, py3.11)	15m 2s
Python Tests (macos-latest, py3.13)	17m 52s
Python Tests (windows-latest, py3.13)	44m 18s
Python Tests (ubuntu-24.04-arm, py3.11)	18m 33s
	4h 53m 22s

Provide feedback