add support for RAG queries to sql parser

[dusvyat]

see mindsdb/mindsdb#8075

[github-actions]

Coverage Report

File	Stmts	Miss	Cover	Missing
mindsdb_sql
__about__.py	10	10	0%	1–10
__init__.py	24	1	96%	21
mindsdb_sql/parser
lexer.py	166	1	99%	244
logger.py	19	4	79%	14, 17, 23, 26
parser.py	456	21	95%	92, 121–128, 182, 199, 317, 346–347, 367, 378, 491, 526, 557, 567, 581, 657
utils.py	46	4	91%	73–79
mindsdb_sql/parser/ast
base.py	36	4	89%	13, 28, 31, 51
create.py	60	16	73%	7–8, 49–54, 73–85
drop.py	52	2	96%	10, 13
insert.py	62	5	92%	32, 35–37, 42
show.py	48	1	98%	18
update.py	53	5	91%	40–42, 75–76
mindsdb_sql/parser/ast/select
case.py	26	2	92%	19, 22
constant.py	42	1	98%	21
data.py	11	2	82%	15, 19
identifier.py	64	7	89%	43, 80–85
operation.py	113	6	95%	27–30, 56, 65, 166
parameter.py	11	1	91%	10
select.py	97	3	97%	148–153
star.py	12	2	83%	8–9
mindsdb_sql/parser/dialects/mindsdb
create_file.py	19	1	95%	14
create_predictor.py	88	1	99%	54
knowledge_base.py	40	1	98%	71
parser.py	927	30	97%	122, 127, 158, 162, 178, 292, 316, 326, 388, 390, 482, 494, 626, 643, 667–668, 794, 844, 893, 910, 1042, 1052, 1090–1091, 1116, 1127, 1267, 1271, 1325, 1728
rag.py	52	11	79%	72, 114–116, 119–123, 126–130
mindsdb_sql/parser/dialects/mysql
lexer.py	23	6	74%	16, 18, 20, 32, 34, 36
parser.py	611	16	97%	116, 118, 210, 222, 341, 358, 486, 496, 534–535, 555, 566, 695, 751, 895, 1041
show_index.py	17	11	35%	10–12, 15–23, 26–27
mindsdb_sql/planner
query_plan.py	22	8	64%	13–21, 30
query_planner.py	721	52	93%	47–48, 71–72, 81, 97, 158, 371, 428, 502, 506, 512, 575–583, 633, 717, 756, 765, 798, 803, 831, 836, 849, 851, 868, 872, 900–917, 935–936, 981, 988, 1011–1012, 1053, 1127, 1154, 1180, 1245, 1292, 1317–1319
query_prepare.py	286	62	78%	76, 78, 86–116, 190, 227, 249, 272, 315, 336, 360, 389–443, 446–452, 483, 496–498, 507, 526
step_result.py	14	2	86%	7, 12
steps.py	168	3	98%	14, 19, 27
ts_utils.py	50	2	96%	58, 60
utils.py	245	39	84%	10–22, 59, 84, 123, 141, 153, 165, 168, 180, 210, 223, 238, 244, 249, 256, 258, 263, 268–271, 276, 281, 287, 293, 307, 337–338, 349–350
mindsdb_sql/render
sqlalchemy_render.py	366	52	86%	38, 72, 74, 86, 91, 163–164, 177–178, 202, 232, 234, 263, 275, 281, 332, 396, 444, 459, 469–470, 494–505, 524, 547–571, 582–583, 588–589, 600–603, 623–626
TOTAL	6089	395	94%

Tests	Skipped	Failures	Errors	Time
684	5 💤	0 ❌	0 🔥	16.255s ⏱️