refactor: cleanup gravity constant handling (#35866)

* refactor: move lateral methods from init to lateral.py (#2594)

* Extracting lateral methods to lateral.py

* cleaning

* more cleaning

* more cleaning

* Making sure it remains where it should

* Leave rate_limit where it belongs

* Moving things to `car/controls/`

* Moving rate limit to get a taste of the changes

* clean

* copy verbatim

* clean up

* more

* now we can format

---------

Co-authored-by: Shane Smiskol <shane@smiskol.com>

* No need to change order of import

* refactor: consolidate ACCELERATION_DUE_TO_GRAVITY import path

* bump opendbc

* update refs

* don't import from opendbc

---------

Co-authored-by: Shane Smiskol <shane@smiskol.com>
Co-authored-by: Adeeb Shihadeh <adeebshihadeh@gmail.com>

common/constants.py

@@ -0,0 +1,23 @@
+import numpy as np
+
+# conversions
+class CV:
+  # Speed
+  MPH_TO_KPH = 1.609344
+  KPH_TO_MPH = 1. / MPH_TO_KPH
+  MS_TO_KPH = 3.6
+  KPH_TO_MS = 1. / MS_TO_KPH
+  MS_TO_MPH = MS_TO_KPH * KPH_TO_MPH
+  MPH_TO_MS = MPH_TO_KPH * KPH_TO_MS
+  MS_TO_KNOTS = 1.9438
+  KNOTS_TO_MS = 1. / MS_TO_KNOTS
+
+  # Angle
+  DEG_TO_RAD = np.pi / 180.
+  RAD_TO_DEG = 1. / DEG_TO_RAD
+
+  # Mass
+  LB_TO_KG = 0.453592
+
+
+ACCELERATION_DUE_TO_GRAVITY = 9.81  # m/s^2