Implement the time integration method used in DualSPHysics and add docs for time integration

[efaulhaber]

Supersedes #693.
Closes #683.

Find the rendered docs for this PR here:
https://trixi-framework.github.io/TrixiParticles.jl/previews/PR716/

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 2 lines in your changes missing coverage. Please review.

Project coverage is 70.50%. Comparing base (6d04215) to head (5927b88).

Files with missing lines	Patch %	Lines
src/general/time_integration.jl	0.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #716      +/-   ##
==========================================
- Coverage   70.53%   70.50%   -0.03%     
==========================================
  Files          96       97       +1     
  Lines        5976     5978       +2     
==========================================
  Hits         4215     4215              
- Misses       1761     1763       +2     

Flag	Coverage Δ
unit	70.50% <0.00%> (-0.03%)	⬇️

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[svchb]

Update News.md

[LasNikas]

Awesome! Thanks a lot

Can this only be used for WCSPH? It shouldn't be hard to add the EDAC scheme, right?
I mean, instead of evolving the density, we evolve the pressure.

[LasNikas]

Mention why we set save_everystep=false?

[efaulhaber]

You can always use the original LeapfrogDriftKickDrift (which I recently added to OrdinaryDiffEq.jl and is available in the latest release) with EDAC, which treats pressure (or density for WCSPH) in the same way as the velocity. I haven't found an advantage of SymplecticPositionVerlet over LeapfrogDriftKickDrift yet.

[svchb]

Suggested change

	- The symplectic time integration scheme from DualSPHysics was added (#716)
	- The symplectic time integration scheme based on DualSPHysics was added (#716)

[efaulhaber]

Suggested change

	- The symplectic time integration scheme from DualSPHysics was added (#716)
	- The symplectic time integration scheme used in DualSPHysics was added (#716)

Better maybe?

[svchb]

Also fine