Enh/in between years season

[bzah]

Pull Request to resolve #162

• Unit tests cover the changes.
• These changes were tested on real data.
• The relevant documentation has been added or updated.
• A short description of the changes has been added to doc/source/references/release_notes.rst.

Describe the changes you made

Added the possibility to create a season between two dates using slice_mode.

slice_mode=["season", ["15 june", "25-08"] ]

Various date format are accepted thanks to dateparser library.
I think we should try to use it as well on time_range and base_periode_time_range parameters

wip:

• wait for xclim PR to be merged
• List all indices where season cannot be computed on
• Forbid calling these indices in icclim with a seasonal slice_mode

[github-actions]

Report

File	Stmts	Miss	Cover	Missing
icclim
ecad_functions.py	267	41	85%	769–803, 807–812, 991–992, 1017, 1042, 1044, 1076
icclim_exceptions.py	17	4	76%	18, 32, 43, 46
icclim_logger.py	86	33	62%	21–24, 46, 58, 68, 73–98, 108, 114–145, 153–158
main.py	197	25	87%	69, 232, 271, 289, 310–311, 313, 336–340, 354–356, 379–386, 408, 416, 418–419, 423, 453
utils.py	14	2	86%	10, 21
icclim/clix_meta
clix_meta_indices.py	42	1	98%	56
icclim/models
cf_calendar.py	34	1	97%	68
ecad_indices.py	89	1	99%	458
frequency.py	177	5	97%	294, 301, 352, 378, 430
index_config.py	116	20	83%	129, 143, 161, 170–173, 187, 207, 214, 223, 234, 243, 250, 255–263
netcdf_version.py	13	4	69%	14–17
quantile_interpolation.py	15	5	67%	15–19
user_index_config.py	106	9	92%	41–44, 59, 88, 178, 180, 184
icclim/pre_processing
input_parsing.py	47	1	98%	30
rechunk.py	86	2	98%	39, 129
icclim/tests
test_rechunk.py	25	2	92%	62, 90
icclim/user_indices
calc_operation.py	76	1	99%	188
operators.py	181	42	77%	104, 187, 200, 203, 220–229, 235–251, 321, 333, 339, 344, 364, 366, 385, 393–394, 413, 422, 430, 442, 461–485
stat.py	17	9	47%	14, 26–32, 40–42
TOTAL	2771	208	92%

Test results

Tests	Skipped	Failures	Errors	Time
183	0 💤	0 ❌	0 🔥	41.831s ⏱️