Support TEXTUAL CONVENTION v1

[ddolcimascolo]

Hi,

Thanks for maintaining this library. Currently the MIB parser correctly parses TEXTUAL CONVENTION v1 but these are not returned by the store.getSyntaxTypes() method. This is because there's no TEXTUAL-CONVENTION macro, the definition directly follows the object name.

See: https://www.ibm.com/docs/en/netcoolomnibus/8.1?topic=snmp-valid-mib-object-formats#omn_ref_mib_formats__title__2

DellStateCapabilities           ::= INTEGER {
    -- If set to 0 (zero), object has no state capabilities
    unknownCapabilities(1),     -- object's state capabilities are unknown
    -- The object's state capabilities allow it to be set to:
    enableCapable(2),           -- be disabled (offline) or be enabled (online)
    notReadyCapable(4),         -- not ready
    enableAndNotReadyCapable(6)
}

Another (simpler) example

DellBoolean                     ::= INTEGER (0..1)    -- 0 = FALSE, 1 = TRUE

Is this something you'll want to support?

I can share a MIB holding such definitions, just ask.

Thanks, David