Switch raw_celestial_state computation to tuple of u64

I cannot seem to match exactly the SPICE ephemeris output. Hence, I'll need to rewrite raw_celestial_state to support a JDE provided a tuple of u64 or u128 ?!

Playing around with extra numbers to add to the JDE value, I cannot get better than the following using a f64:

[src/celestia/cosm.rs:619] jde = 2452312.500742881
[src/celestia/cosm.rs:620] test_epoch.as_et_seconds() = 66312064.18493939
[src/celestia/cosm.rs:634] ven2ear_state.x - 2.0512621957200775e+08 = -0.0004665553569793701
[src/celestia/cosm.rs:635] ven2ear_state.y - -1.3561254792308527e+08 = -0.0006327331066131592
[src/celestia/cosm.rs:636] ven2ear_state.z - -6.5578399676151529e+07 = -0.0002679303288459778
[src/celestia/cosm.rs:637] ven2ear_state.vx - 3.6051374278177832e+01 = 0.00000000019305446130601922
[src/celestia/cosm.rs:638] ven2ear_state.vy - 4.8889024622170766e+01 = -0.00000000007790390554873738
[src/celestia/cosm.rs:639] ven2ear_state.vz - 2.0702933800843084e+01 = -0.0000000000432756053214689
[src/celestia/cosm.rs:645] moon_from_emb.x - -8.1576591043050896e+04 = -0.000012433214578777552
[src/celestia/cosm.rs:646] moon_from_emb.y - -3.4547568914480874e+05 = 0.0000026347115635871887
[src/celestia/cosm.rs:647] moon_from_emb.z - -1.4439185901465410e+05 = 0.000002378743374720216
[src/celestia/cosm.rs:648] moon_from_emb.vx - 9.6071184439702662e-01 = -0.00000000000756694706893768
[src/celestia/cosm.rs:649] moon_from_emb.vy - -2.0358322542180365e-01 = -0.00000000003090014355500159
[src/celestia/cosm.rs:650] moon_from_emb.vz - -1.8380551745739407e-01 = -0.00000000001291183826523934
[src/celestia/cosm.rs:654] earth_from_emb.x - 1.0033950894874154e+03 = 0.00000015292891930585029
[src/celestia/cosm.rs:655] earth_from_emb.y - 4.2493637646888546e+03 = -0.000000032406205718871206
[src/celestia/cosm.rs:656] earth_from_emb.z - 1.7760252107225667e+03 = -0.000000029258671929710545
[src/celestia/cosm.rs:657] earth_from_emb.vx - -1.1816791248014408e-02 = 0.00000000000009307485338005961
[src/celestia/cosm.rs:658] earth_from_emb.vy - 2.5040812085717632e-03 = 0.0000000000003800731430969595
[src/celestia/cosm.rs:659] earth_from_emb.vz - 2.2608146685133296e-03 = 0.00000000000015881653631089065
[Geoid 399] 52312.00074288109   position = [-82579.986145, -349725.052907, -146167.884223] km   velocity = [0.972529, -0.206087, -0.186066] km/s
[src/celestia/cosm.rs:669] moon_from_earth.x - -8.2579986132538310e+04 = -0.000012586140655912459
[src/celestia/cosm.rs:670] moon_from_earth.y - -3.4972505290949758e+05 = 0.0000026670750230550766
[src/celestia/cosm.rs:671] moon_from_earth.z - -1.4616788422537665e+05 = 0.000002407992724329233
[src/celestia/cosm.rs:672] moon_from_earth.vx - 9.7252863564504100e-01 = -0.000000000007659983758401268
[src/celestia/cosm.rs:673] moon_from_earth.vy - -2.0608730663037542e-01 = -0.000000000031280228407482014
[src/celestia/cosm.rs:674] moon_from_earth.vz - -1.8606633212590740e-01 = -0.000000000013070655668911968