CDRIVER-4122 Add BSON corpus test for binary subtype 7

[eramongodb]

Validating changes relating to DRIVERS-1875.

[jmikola]

Passes in PHPC.

Note: after merging, make sure you update the downstream change summary on DRIVERS-1875 to advise drivers to create a new constant for sub-type 0x07 (please suggest a name) and sync their BSON corpus tests to the merge commit.

[eramongodb]

Note: after merging, make sure you update the downstream change summary on DRIVERS-1875 to advise drivers to create a new constant for sub-type 0x07 (please suggest a name) and sync their BSON corpus tests to the merge commit.

@jmikola Per name in server, the name will likely be <subtype-prefix>Column where <subtype-prefix> depends on the given language. For the C driver, this would be:

  typedef enum {
     BSON_SUBTYPE_BINARY = 0x00,
     BSON_SUBTYPE_FUNCTION = 0x01,
     BSON_SUBTYPE_BINARY_DEPRECATED = 0x02,
     BSON_SUBTYPE_UUID_DEPRECATED = 0x03,
     BSON_SUBTYPE_UUID = 0x04,
     BSON_SUBTYPE_MD5 = 0x05,
     BSON_SUBTYPE_ENCRYPTED = 0x06,
+    BSON_SUBTYPE_COLUMN = 0x07,
     BSON_SUBTYPE_USER = 0x80,
  } bson_subtype_t;

Should the addition of this enumeration constant be included in this PR?

[jmikola]

Should the addition of this enumeration constant be included in this PR?

I think so, as it's part of the changes that should be proposed by DRIVERS-1875.

I didn't realize this was a libmongoc PR when I left my previous comment. That was intended for mongodb/specifications#1065, so I'll copy it there. The DRIVERS ticket should definitely be revised to suggest drivers add a constant for the new subtype if they currently do so for other subtypes, and that would be a reasonable place to suggest "COLUMN" as a name.