Store target map in a flatbuffer

Mapping process takes input json with initial guesses for target poses,
and outputs a json with the solved poses.

Signed-off-by: Milind Upadhyay <milind.upadhyay@gmail.com>
Change-Id: I29b82aacd37758e7dc8d8cd383821899182a1950
diff --git a/frc971/vision/BUILD b/frc971/vision/BUILD
index 7872926..54dab0d 100644
--- a/frc971/vision/BUILD
+++ b/frc971/vision/BUILD
@@ -88,6 +88,14 @@
     ],
 )
 
+flatbuffer_cc_library(
+    name = "target_map_fbs",
+    srcs = ["target_map.fbs"],
+    gen_reflections = 1,
+    target_compatible_with = ["@platforms//os:linux"],
+    visibility = ["//visibility:public"],
+)
+
 cc_library(
     name = "target_mapper",
     srcs = ["target_mapper.cc"],
@@ -96,6 +104,7 @@
     visibility = ["//visibility:public"],
     deps = [
         ":geometry_lib",
+        ":target_map_fbs",
         "//aos/events:simulated_event_loop",
         "//frc971/control_loops:control_loop",
         "//frc971/vision/ceres:pose_graph_2d_lib",