Identify and optitonal filter noisy data points

[tsuzzy]

Currently, AISdb includes function for AIS data cleaning such as encode_greatcircledistance(), but the criteria for identifying noisy data points need to be enhanced and the users should have control over whether to remove identified noise or retain the data based on their specific needs. To improve accuracy and flexibility of current function, it would be beneficial to:

1. Clarify the default criteria used for identifying and removing noisy data points, including parameters like speed and distance thresholds, invalid coordinates, etc.
2. Customizable noise filtering which allows users to identify noises and decide whether to remove or retain flagged noise points.