Rename internal variables and methods to start with _ (#304)

* Fix typo

* Rename quantitiesList to _quantitiesList

* Rename paramlist to _paramlist

* Rename inputlist to _inputlist

* Rename outputlist to _outputlist

* Rename continuouslist to _continuouslist

* Rename simulateOptions to _simulateOptions

* Rename overridevariables to _overridevariables

* Rename simoptionsoverride to _simoptionsoverride

* Rename linearOptions to _linearOptions

* Rename optimizeOptions to _optimizeOptions

* Rename linearinputs to _linearinputs

* Rename linearoutputs to _linearoutputs

* Rename linearstates to _linearstates

* Improve docstrings for getLinear*()

* Rename xmlFile to _xmlFile

* Rename lmodel to _lmodel

* Rename modelName to _modelName

* Rename fileName to _fileName

* Rename inputFlag to _inputFlag

* Rename simulationFlag to _simulationFlag

* Remove unused variable outputFlag

* Rename csvFile to _csvFile

* Rename resultfile to _resultfile

* Rename variableFilter to _variableFilter

* Rename getconn to _getconn

* Rename tempdir to _tempdir

* Rename xmlparse() to _xmlparse()

* Rename checkValidInputs() to _checkValidInputs()

* Rename createCSVData() to _createCSVData()

* Rename loadFile() to _loadFile()

* Rename loadLibrary() to _loadLibrary()

* Rename requestApi() to _requestApi()

* Rename setMethodHelper() to _setMethodHelper()

* Improve docstrings

* Allow float timeouts

The type hints were misleadingly saying int, when in fact subprocess.run
accepts float timeouts.

* Improve docstring for simulate()

* Improve docstrings

* Improve ModelicaSystemCmd docstrings

* Improve docstring for getContinuous()

* Improve docstring for getSimulationOptions()

* Improve docstring for getLinearizationOptions()

* Improve docstring for getOptimizationOptions()

* Improve docstring for getSolutions()

* Improve docstring for optimize()

* Improve docstring for convertMo2Fmu()

* Rename _quantitiesList to _quantities

* Rename _paramlist to _params

* Rename _inputlist to _inputs

* Rename _outputlist to _outputs

* Rename _continuouslist to _continuous

* Rename _simulateOptions to _simulate_options

* Rename _overridevariables to _override_variables

* Rename _simoptionsoverride to _simulate_options_override

* Rename _linearOptions to _linearization_options

* Rename _optimizeOptions to _optimization_options

* Rename _linearinputs to _linearized_inputs

* Rename _linearoutputs to _linearized_outputs

* Rename _linearstates to _linearized_states

* Rename _xmlFile to _xml_file

* Rename _modelName to _model_name

* Rename _fileName to _file_name

* Rename _inputFlag to _has_inputs

* Rename _simulationFlag to _simulated

* Rename _resultfile to _result_file

* Rename _variableFilter to _variable_filter

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Co-authored-by: Adeel Asghar <[email protected]>

Author: ondras12345