Deprecate config parameters for the new logging

[sblauth]

With the new logging capabilities, the parameters

[Output]
verbose
save_txt

will be obsolte, as well as the FileManager for outputting the history of the optimization with the save_txt parameter. These should be removed.

Additionally, most of the places where a "verbose" parameter is used to control the output, this should be replaced by logging.

[sblauth]

Configuration Parameters that are deprecated

Section StateSystem

• picard_verbose
• newton_verbose

Section Output

• verbose

Function paramters that are deprecated

• cashocs.nonlinear_solvers.newton_solve - verbose
• cashocs.nonlinear_solvers.picard_iteration - verbose
• cashocs.space_mapping.solve - verbose
• cashocs.space_mapping.solve - save_history

These parts should be accessed as part of the logging module

• cashocs.set_log_level -> cashocs.log.set_log_level
• cashocs.LogLevel.INFO -> cashocs.log.INFO (and analogously for the other levels)