Mk filtered

[monicakochofar]

Requirements:
Given the user is viewing the map, when they filter out bins, then the filtered-out bins map markers are kept on the map but transparent
Given the user is viewing the map and filters, when the bins are part of the current filter, then their bin map markers remain coloured.

Dev Notes:
The app had been developed with the idea that sensors that are filtered out are removed from viewing/use. Now that we want to show all sensors and just lower the opacity of the ones that are filtered out, we needed to do some refactoring in our code to accomodate.
Refactoring includes:

• renaming variables
• removing unused variables
• refactoring app_vue/src/utils/mapMarkerHelper.js to be more simplistic in useage (less hardcoding strings)
• bin icons that are low opacity are now marked with low-opacity css class

result: