Migrate to SQLite DB from JSON files

[ckreisl]

fixes #5

Introduce a proper sqlite database to store any kind of data.
JSON files are to error prone if multiple users are interacting with the system.

[github-actions]

Coverage Report

File	Stmts	Miss	Cover	Missing
__init__.py	0	0	100%
crawler.py	30	0	100%
cs2.py	83	10	87%	30, 37, 42, 50, 68, 89, 105, 118–120
db.py	207	21	89%	52, 73–76, 155, 157–158, 161–166, 352, 354–355, 358–359, 361–362
post.py	79	2	97%	21, 61
bot
__init__.py	0	0	100%
chats.py	21	0	100%
constants.py	4	0	100%
content.py	76	6	92%	28, 49, 62, 90, 100, 106
cs2.py	292	87	70%	37–42, 44–46, 97–99, 101–102, 104–106, 108–109, 111, 114, 116–120, 122–125, 127, 136, 140–143, 192, 306–309, 312–313, 315–316, 318, 320, 323–325, 328–329, 331–332, 334, 336, 339–341, 344–345, 347, 349–350, 352, 354, 357–359, 369, 371–373, 375–377, 379, 422, 424–426, 432, 434–436, 439, 442
decorators.py	3	3	0%	1, 3, 5
message.py	163	33	79%	83–86, 99, 120, 122, 132, 134–135, 137, 139–141, 150–153, 155, 167–170, 210, 213, 220, 222, 225–226, 241, 248–249, 266
options.py	98	20	79%	34, 41–43, 48–50, 52, 69, 73–74, 78, 80, 82, 85–87, 89, 159–160
settings.py	17	0	100%
spam.py	71	0	100%
utils.py	24	0	100%
parser
__init__.py	0	0	100%
parser.py	14	1	92%	21
steam2telegram_html.py	26	0	100%
steam_list.py	52	0	100%
steam_news_image.py	16	0	100%
steam_news_youtube.py	12	0	100%
steam_update_heading.py	21	0	100%
TOTAL	1309	183	86%

Tests	Skipped	Failures	Errors	Time
137	0 💤	0 ❌	0 🔥	3.984s ⏱️