Make sure we geometrically grow the capacity of the particle buffers

[atmyers]

This makes a significant performance difference on a problem setup @aeriforme gave me. In this simulation, many particles leave the domain and we need to store them all for analysis.

On development:

TinyProfiler total time across processes [min...avg...max]: 4246 ... 4246 ... 4246

-------------------------------------------------------------------------------------------------------------
Name                                                          NCalls  Excl. Min  Excl. Avg  Excl. Max   Max %
-------------------------------------------------------------------------------------------------------------
ParticleBoundaryBuffer::gatherParticles::resize                 8772       3843       3843       3843  90.49%
WarpXOpenPMDPlot::SeriesFlush()()                                 96      89.46      89.46      89.46   2.11%
ParticleBoundaryBuffer::gatherParticles                          256      58.11      58.11      58.11   1.37%
ParticleContainer::addParticles                                   48      53.54      53.54      53.54   1.26%
ParticleBoundaryBuffer::gatherParticles::filterAndTransform     8772      27.26      27.26      27.26   0.64%

This PR:

TinyProfiler total time across processes [min...avg...max]: 494.6 ... 494.6 ... 494.6

-------------------------------------------------------------------------------------------------------------
Name                                                          NCalls  Excl. Min  Excl. Avg  Excl. Max   Max %
-------------------------------------------------------------------------------------------------------------
ParticleBoundaryBuffer::gatherParticles::resize                 8754      126.3      126.3      126.3  25.53%
WarpXOpenPMDPlot::SeriesFlush()()                                 96       90.3       90.3       90.3  18.26%
ParticleContainer::addParticles                                   48      59.01      59.01      59.01  11.93%
FFT::R2C::forward(in)                                           1934      27.05      27.05      27.05   5.47%
ParticleBoundaryBuffer::gatherParticles::filterAndTransform     8754       26.8       26.8       26.8   5.42%

[AlexanderSinn]

The resize_geometric_grow() function from AMReX-Codes/amrex#4529 could make this simpler

[atmyers]

Note that I bumped the AMReX version for AMReX-Codes/amrex#4708

[RemiLehe]

Thanks a lot for this PR!