Removed unnecessary directory "checks" from within the regressionchec…

…k folder and removed all references in other files such as the user guide and gitlab-ci. Additionally, all .pvsm (ParaView Layouts) files have been removed.

docs/documentation/developerguide/reggie.md

@@ -16,7 +16,7 @@ regression test is described there.
 
 Different tests are executed on check-in, during nightly or weekly testing. These tests are defined
 in the file *.gitlab-ci.yml* that is located in the top level repository directory of PICLas. In
-this file, various tests are defined, which are found under *regressioncheck/checks* and a summary
+this file, various tests are defined, which are found under *regressioncheck* and a summary
 of the different tests is given under https://github.com/piclas-framework/piclas/blob/master/REGGIE.md
 
 The automatic execution by *gitlab-runners* can be performed on any machine that is connected to the

docs/documentation/userguide/features-and-models/DSMC.md

@@ -256,7 +256,7 @@ particle has a specific electronic state and the model by Burt and Eswar {cite}`
 distribution function attached. Both models utilize tabulated energy levels, which can be found in literature for a wide range of
 species (e.g. for monatomic {cite}`NISTASD`, diatomic {cite}`Huber1979`, polyatomic {cite}`Herzberg1966` molecules). An example
 database `DSMCSpecies_electronic_state_full_Data.h5` can be found in e.g.
-`piclas/regressioncheck/checks/NIG_Reservoir/CHEM_EQUI_TCE_Air_5Spec`, where the energy levels are stored in containers and
+`piclas/regressioncheck/NIG_Reservoir/CHEM_EQUI_TCE_Air_5Spec`, where the energy levels are stored in containers and
 accessed via the species name, e.g. `Part-Species1-SpeciesName=N2`. Each level is described by its degeneracy in the first column
 and by the energy in [J] in the second column. To include electronic excitation in the simulation, the following parameters are
 required
@@ -346,15 +346,15 @@ activation energy [K]. These parameters can be defined in PICLas as follows
     DSMC-Reaction1-Activation-Energy_K=113200.0
 
 An example initialization file for a TCE-based chemistry model can be found in the regression tests (e.g.
-`regressioncheck/checks/NIG_Reservoir/CHEM_EQUI_TCE_Air_5Spec`).
+`regressioncheck/NIG_Reservoir/CHEM_EQUI_TCE_Air_5Spec`).
 
 ### Quantum Kinetic Chemistry (QK)
 
 The Quantum Kinetic (QK) model {cite}`Bird2011` chooses a different approach and models chemical reactions on the microscopic level.
 Currently, the QK model is only available for ionization and dissociation reactions. It is possible to utilize TCE- and QK-based
 reactions in the same simulation for different reactions paths for the same collision pair, such as the ionization and dissociation
 reactions paths (e.g. N$_2$ + e can lead to a dissociation with the TCE model and to an ionization with the QK model).
-An example setup can be found in the regression tests (e.g. `regressioncheck/checks/NIG_Reservoir/CHEM_QK_multi-ionization_C_to_C6+`).
+An example setup can be found in the regression tests (e.g. `regressioncheck/NIG_Reservoir/CHEM_QK_multi-ionization_C_to_C6+`).
 
 Besides the reaction model, reactants and products definition no further parameter are required for the reaction. However,
 the dissociation energy [eV] has to be defined on a species basis
@@ -374,7 +374,7 @@ reactions named by their products, e.g. `N2Ion1-electron-electron`.
 If the defined reaction cannot be found in the database, the code will abort. It should be noted that this model is not limited to
 the utilization with MCC or a background gas and can be used with conventional DSMC as an alternative chemistry model. Here, the
 probability will be added to the collision probability to reproduce the reaction rate. Examples of the utilization of this model
-can be found in the regression tests (e.g. `regressioncheck/checks/NIG_Reservoir/CHEM_RATES_XSec_Chem_H2-e`).
+can be found in the regression tests (e.g. `regressioncheck/NIG_Reservoir/CHEM_RATES_XSec_Chem_H2-e`).
 ### Backward Reaction Rates
 
 Backward reaction rates can be calculated for any given forward reaction rate by using the equilibrium constant