Use SVector in all trace methods

[henry2004y]

Check if the usage of SVector is helpful in all cases.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 84.27%. Comparing base (c8cb82e) to head (1468f6f).
Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #207      +/-   ##
==========================================
- Coverage   84.46%   84.27%   -0.19%     
==========================================
  Files           9        9              
  Lines         695      687       -8     
==========================================
- Hits          587      579       -8     
  Misses        108      108              

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[github-actions]

Benchmark Results

	master	1468f6f...	master/1468f6feb55575...
trace/GC/in place	0.15 ± 0.045 ms	0.153 ± 0.046 ms	0.98
trace/analytic field/in place	6.71 ± 3.3 μs	8.89 ± 3.4 μs	0.754
trace/analytic field/in place relativistic	9.5 ± 3.3 μs	9.61 ± 3.3 μs	0.989
trace/analytic field/out of place	6.15 ± 2.7 μs	5.98 ± 2.7 μs	1.03
trace/numerical field/Boris	2.24 ± 0.16 μs	2.25 ± 0.15 μs	0.996
trace/numerical field/Boris ensemble	4.29 ± 0.96 μs	4.3 ± 0.92 μs	0.999
trace/numerical field/in place	20.7 ± 3.4 μs	20.8 ± 3.4 μs	0.991
trace/numerical field/out of place	15.7 ± 2.2 μs	15.5 ± 2.6 μs	1.01
trace/time-dependent field/in place	10.2 ± 3.6 μs	8.47 ± 3.5 μs	1.21
trace/time-dependent field/out of place	7.41 ± 2.9 μs	7.3 ± 2.9 μs	1.02
time_to_load	2.12 ± 0.0096 s	2.11 ± 0.039 s	1

	master	1468f6f...	master/1468f6feb55575...
trace/GC/in place	2.29 k allocs: 0.12 MB	2.29 k allocs: 0.12 MB	1
trace/analytic field/in place	0.199 k allocs: 10.5 kB	0.199 k allocs: 10.5 kB	1
trace/analytic field/in place relativistic	0.199 k allocs: 10.5 kB	0.199 k allocs: 10.5 kB	1
trace/analytic field/out of place	0.159 k allocs: 8.61 kB	0.159 k allocs: 8.61 kB	1
trace/numerical field/Boris	19 allocs: 1.88 kB	19 allocs: 1.88 kB	1
trace/numerical field/Boris ensemble	25 allocs: 3.3 kB	25 allocs: 3.3 kB	1
trace/numerical field/in place	0.2 k allocs: 12.7 kB	0.2 k allocs: 12.7 kB	1
trace/numerical field/out of place	0.159 k allocs: 9.81 kB	0.159 k allocs: 9.81 kB	1
trace/time-dependent field/in place	0.22 k allocs: 11.3 kB	0.22 k allocs: 11.3 kB	1
trace/time-dependent field/out of place	0.177 k allocs: 9.39 kB	0.177 k allocs: 9.39 kB	1
time_to_load	0.157 k allocs: 11.1 kB	0.157 k allocs: 11.1 kB	1

[Beforerr]

BTW vcat(v, dv) is faster than SVector{6}(v..., dv...)

[henry2004y]

BTW vcat(v, dv) is faster than SVector{6}(v..., dv...)

Based on my test, the time difference is almost negligible.