New Departures and Deviations based on new SL Traffic API

[NecroKote]

This PR adresses #68 #67

This PR contains:

• better config_flow based on latest HA helpers
• new Departures and Deviations sensors, based on the new SL Traffic API.
• the SL Traffic API extracted into a separate package trafiklab-sl
• major type hinting improvements
• initial reorganization of the sensor initialization logic making it more modular

IMPORTANT: new sensors are NOT compatible with the existing Departure Card.
This was a necessary sacrifice. But I'm also working on overhauling the Departure Card as well (typescript + Lit would give better maintainability) and should present it soon.

This PR targets the dev branch, as a couple of things still need to be improved before releasing it.
Overall, consider this a major WIP refactoring.

What's missing:

• comments
• translation strings for Swedish
• changelog
• entity migrations
• schema and version bumps
• something else?

[pep8speaks]

Hello @NecroKote! Thanks for opening this PR. We checked the lines you've touched for PEP 8 issues, and found:

• In the file custom_components/hasl3/__init__.py:

Line 25:1: E302 expected 2 blank lines, found 1
Line 37:5: E722 do not use bare 'except'
Line 48:80: E501 line too long (82 > 79 characters)
Line 81:80: E501 line too long (82 > 79 characters)
Line 109:5: E303 too many blank lines (2)
Line 119:80: E501 line too long (85 > 79 characters)
Line 142:5: E303 too many blank lines (2)
Line 151:80: E501 line too long (100 > 79 characters)
Line 156:80: E501 line too long (80 > 79 characters)
Line 179:5: E303 too many blank lines (2)
Line 203:80: E501 line too long (82 > 79 characters)
Line 204:80: E501 line too long (82 > 79 characters)
Line 205:80: E501 line too long (82 > 79 characters)
Line 206:80: E501 line too long (80 > 79 characters)
Line 227:80: E501 line too long (87 > 79 characters)
Line 242:80: E501 line too long (80 > 79 characters)
Line 251:80: E501 line too long (81 > 79 characters)
Line 258:80: E501 line too long (83 > 79 characters)
Line 263:80: E501 line too long (94 > 79 characters)
Line 300:80: E501 line too long (80 > 79 characters)
Line 307:80: E501 line too long (88 > 79 characters)

• In the file custom_components/hasl3/config_flow.py:

Line 42:80: E501 line too long (87 > 79 characters)
Line 45:80: E501 line too long (82 > 79 characters)

• In the file custom_components/hasl3/config_schema.py:

Line 56:80: E501 line too long (95 > 79 characters)
Line 159:80: E501 line too long (82 > 79 characters)

• In the file custom_components/hasl3/sensor.py:

Line 57:1: E266 too many leading '#' for block comment
Line 59:80: E501 line too long (88 > 79 characters)
Line 79:80: E501 line too long (111 > 79 characters)
Line 99:80: E501 line too long (92 > 79 characters)
Line 152:80: E501 line too long (85 > 79 characters)
Line 168:80: E501 line too long (83 > 79 characters)
Line 189:80: E501 line too long (98 > 79 characters)
Line 196:80: E501 line too long (81 > 79 characters)
Line 327:80: E501 line too long (80 > 79 characters)
Line 332:80: E501 line too long (80 > 79 characters)
Line 335:80: E501 line too long (80 > 79 characters)
Line 339:80: E501 line too long (88 > 79 characters)
Line 340:80: E501 line too long (80 > 79 characters)
Line 341:80: E501 line too long (80 > 79 characters)
Line 351:80: E501 line too long (104 > 79 characters)
Line 465:80: E501 line too long (80 > 79 characters)
Line 470:80: E501 line too long (80 > 79 characters)
Line 473:80: E501 line too long (80 > 79 characters)
Line 477:80: E501 line too long (88 > 79 characters)
Line 478:80: E501 line too long (80 > 79 characters)
Line 479:80: E501 line too long (80 > 79 characters)
Line 489:80: E501 line too long (104 > 79 characters)
Line 703:80: E501 line too long (104 > 79 characters)
Line 776:80: E501 line too long (88 > 79 characters)
Line 920:80: E501 line too long (104 > 79 characters)
Line 970:80: E501 line too long (88 > 79 characters)
Line 1034:80: E501 line too long (104 > 79 characters)

• In the file custom_components/hasl3/sensors/departure.py:

Line 35:80: E501 line too long (81 > 79 characters)
Line 141:80: E501 line too long (83 > 79 characters)
Line 168:80: E501 line too long (86 > 79 characters)
Line 177:80: E501 line too long (85 > 79 characters)
Line 258:80: E501 line too long (81 > 79 characters)

• In the file custom_components/hasl3/sensors/status.py:

Line 12:80: E501 line too long (81 > 79 characters)
Line 32:80: E501 line too long (83 > 79 characters)
Line 35:80: E501 line too long (83 > 79 characters)
Line 93:80: E501 line too long (86 > 79 characters)
Line 116:80: E501 line too long (87 > 79 characters)
Line 139:80: E501 line too long (80 > 79 characters)

[systemcrash]

Thanks for undertaking this @NecroKote