issue with V3000 SD files containing enhanced stereochemistry information

[GLPG-GT]

Describe the bug
Chem.SDMolSupplier raises warnings when reading a V3000 SD file made by Dassault/Biovia/Scitegic software, and ignores the enhanced stereochemistry information, whereas the same molecule written out to a V3000 SDF from within rdkit can be read back correctly.

To Reproduce
Run:

with Chem.SDMolSupplier('mol_with_enhanced_stereo_2_And_groups.sdf') as SDF:
    ms2 = [m for m in SDF if m is not None]

on file:
mol_with_enhanced_stereo_2_And_groups.sdf.txt
after renaming it to .sdf (GitHub did not accept sdf as file type)

For comparison, run:

with Chem.SDMolSupplier('m_with_enh_stereo.sdf') as SDF:
    ms = [m for m in SDF if m is not None]

on file:
m_with_enh_stereo.sdf.txt
(again after renaming it to .sdf).

Expected behavior
Both files should result in a V3000 MolBlock like the following:

 RDKit          2D

0 0 0 0 0 0 0 0 0 0999 V3000
M V30 BEGIN CTAB
M V30 COUNTS 22 24 0 0 0
M V30 BEGIN ATOM
M V30 1 O 7.414605 -6.052405 0.000000 0
M V30 2 C 6.201079 -6.934083 0.000000 0
M V30 3 N 4.830761 -6.323978 0.000000 0
M V30 4 C 4.673969 -4.832195 0.000000 0
M V30 5 C 3.303650 -4.222090 0.000000 0
M V30 6 C 2.004612 -4.972090 0.000000 0
M V30 7 C 0.889895 -3.968394 0.000000 0
M V30 8 C 1.500000 -2.598076 0.000000 0
M V30 9 C 0.750000 -1.299038 0.000000 0
M V30 10 C 1.500000 0.000000 0.000000 0
M V30 11 C 0.750000 1.299038 0.000000 0
M V30 12 C -0.750000 1.299038 0.000000 0
M V30 13 C -1.500000 0.000000 0.000000 0
M V30 14 C -0.750000 -1.299038 0.000000 0
M V30 15 O 2.991783 -2.754869 0.000000 0
M V30 16 N 6.357872 -8.425866 0.000000 0
M V30 17 C 7.728190 -9.035971 0.000000 0
M V30 18 C 9.027228 -8.285971 0.000000 0
M V30 19 O 10.141946 -9.289667 0.000000 0
M V30 20 C 9.531841 -10.659985 0.000000 0
M V30 21 C 8.040058 -10.503192 0.000000 0
M V30 22 O 7.036362 -11.617910 0.000000 0
M V30 END ATOM
M V30 BEGIN BOND
M V30 1 2 1 2
M V30 2 1 2 3
M V30 3 1 3 4
M V30 4 1 5 4 CFG=3
M V30 5 1 5 6
M V30 6 1 6 7
M V30 7 1 8 7 CFG=3
M V30 8 1 8 9
M V30 9 2 9 10
M V30 10 1 10 11
M V30 11 2 11 12
M V30 12 1 12 13
M V30 13 2 13 14
M V30 14 1 8 15
M V30 15 1 2 16
M V30 16 1 17 16 CFG=3
M V30 17 1 17 18
M V30 18 1 18 19
M V30 19 1 19 20
M V30 20 1 20 21
M V30 21 1 21 22 CFG=3
M V30 22 1 15 5
M V30 23 1 21 17
M V30 24 1 14 9
M V30 END BOND
M V30 BEGIN COLLECTION
M V30 MDLV30/STERAC1 ATOMS=(2 5 8)
M V30 MDLV30/STERAC2 ATOMS=(2 17 21)
M V30 END COLLECTION
M V30 END CTAB
M END

Instead, the first file (the one causing warnings) results in the following V3000 MolBlock:

2 And groups, from CXSMILES
RDKit 2D

0 0 0 0 0 0 0 0 0 0999 V3000
M V30 BEGIN CTAB
M V30 COUNTS 22 24 0 0 0
M V30 BEGIN ATOM
M V30 1 O 7.414600 -6.052410 0.000000 0
M V30 2 C 6.201080 -6.934080 0.000000 0
M V30 3 N 4.830760 -6.323980 0.000000 0
M V30 4 C 4.673970 -4.832190 0.000000 0
M V30 5 C 3.303650 -4.222090 0.000000 0
M V30 6 C 2.004610 -4.972090 0.000000 0
M V30 7 C 0.889900 -3.968390 0.000000 0
M V30 8 C 1.500000 -2.598080 0.000000 0
M V30 9 C 0.750000 -1.299040 0.000000 0
M V30 10 C 1.500000 0.000000 0.000000 0
M V30 11 C 0.750000 1.299040 0.000000 0
M V30 12 C -0.750000 1.299040 0.000000 0
M V30 13 C -1.500000 0.000000 0.000000 0
M V30 14 C -0.750000 -1.299040 0.000000 0
M V30 15 O 2.991780 -2.754870 0.000000 0
M V30 16 N 6.357870 -8.425870 0.000000 0
M V30 17 C 7.728190 -9.035970 0.000000 0
M V30 18 C 9.027230 -8.285970 0.000000 0
M V30 19 O 10.141950 -9.289670 0.000000 0
M V30 20 C 9.531840 -10.659990 0.000000 0
M V30 21 C 8.040060 -10.503190 0.000000 0
M V30 22 O 7.036360 -11.617910 0.000000 0
M V30 END ATOM
M V30 BEGIN BOND
M V30 1 2 1 2
M V30 2 1 2 3
M V30 3 1 3 4
M V30 4 1 5 4 CFG=3
M V30 5 1 5 6
M V30 6 1 6 7
M V30 7 1 8 7 CFG=3
M V30 8 1 8 9
M V30 9 2 9 10
M V30 10 1 10 11
M V30 11 2 11 12
M V30 12 1 12 13
M V30 13 2 13 14
M V30 14 1 8 15
M V30 15 1 2 16
M V30 16 1 17 16 CFG=3
M V30 17 1 17 18
M V30 18 1 18 19
M V30 19 1 19 20
M V30 20 1 20 21
M V30 21 1 21 22 CFG=3
M V30 22 1 15 5
M V30 23 1 21 17
M V30 24 1 14 9
M V30 END BOND
M V30 END CTAB
M END

Screenshots
Not applicable.

Configuration (please complete the following information):

• RDKit version: 2021.09.2 build py39hccf6a74_0
• OS: CentOS Linux 7
• Python version (if relevant): 3.9.7
• Are you using conda? yes
• If you are using conda, which channel did you install the rdkit from? conda-forge
• If you are not using conda: how did you install the RDKit? NA

Additional context
Not applicable.

[d-b-w]

The specific warnings are:

 In [1]: from rdkit import Chem                                                                                                                                                                                              
 In [2]: Chem.MolFromMolFile('/Users/wandschn/Downloads/mol_with_enhanced_stereo_2_And_groups.sdf')                                                                                                                          
[16:16:42] Skipping unrecognized collection type at line 58: MDLV30/STERAC1 ATOMS=(2 5 8) 
[16:16:42] Skipping unrecognized collection type at line 59: MDLV30/STERAC2 ATOMS=(2 17 21) 

It appears that lines 58 & 59 have trailing spaces. This is absolutely a bug in the regex we're using to parse this line.