[photonlib-py] Begin implementing PhotonPoseEstimator in Python (#1178)

* [photonlib-py] Initial impl of PhotonPoseEstimator

---------

Co-authored-by: Matt <matthew.morley.ca@gmail.com>

photon-lib/py/photonlibpy/estimatedRobotPose.py

@@ -0,0 +1,26 @@
+from dataclasses import dataclass
+from typing import TYPE_CHECKING
+
+from wpimath.geometry import Pose3d
+
+from .photonTrackedTarget import PhotonTrackedTarget
+
+if TYPE_CHECKING:
+    from .photonPoseEstimator import PoseStrategy
+
+
+@dataclass
+class EstimatedRobotPose:
+    """An estimated pose based on pipeline result"""
+
+    estimatedPose: Pose3d
+    """The estimated pose"""
+
+    timestampSeconds: float
+    """The estimated time the frame used to derive the robot pose was taken"""
+
+    targetsUsed: [PhotonTrackedTarget]
+    """A list of the targets used to compute this pose"""
+
+    strategy: "PoseStrategy"
+    """The strategy actually used to produce this pose"""