PWFA 1D: Fix output name

Hard coded, undocumented convention: turns out this must be the name
of the test that we define in the ini file. Logical, isn't it. Not.

Follow-up to #2593

Author: ax3l

Examples/Physics_applications/plasma_acceleration/PICMI_inputs_plasma_acceleration_1d.py

@@ -53,7 +53,7 @@
                                    period = max_steps,
                                    data_list = ['Ex', 'Ey', 'Ez', 'Jx', 'Jy', 'Jz', 'part_per_cell'],
                                    write_dir = '.',
-                                   warpx_file_prefix = 'Python_PlasmaAcceleration_plt')
+                                   warpx_file_prefix = 'Python_PlasmaAcceleration1d_plt')
 
 part_diag = picmi.ParticleDiagnostic(name = 'diag1',
                                      period = max_steps,

Regression/Checksum/benchmarks_json/Python_PlasmaAcceleration_1d.json renamed to Regression/Checksum/benchmarks_json/Python_PlasmaAcceleration1d.json

@@ -1624,7 +1624,7 @@ particleTypes = beam
 analysisRoutine = Examples/analysis_default_regression.py
 tolerance = 1.e-14
 
-[Python_PlasmaAcceleration_1d]
+[Python_PlasmaAcceleration1d]
 buildDir = .
 inputFile = Examples/Physics_applications/plasma_acceleration/PICMI_inputs_plasma_acceleration_1d.py
 runtime_params =