Deadlock in SQL SERVER 2014
Just my 5 cents contribution to the topic (not a complete answer)

I had a similar issue and I've caught the blocking query with sp_whoisactive - so it is

create procedure sys.sp_columns_100
(
    @table_name         nvarchar(384),
    @table_owner        nvarchar(384) = null,
    @table_qualifier    sysname = null,
    @column_name        nvarchar(384) = null,
    @NameScope          int = 0,
    @ODBCVer            int = 2,
    @fUsePattern        bit = 1 -- To allow users to explicitly disable all pattern matching.
)
...


and as @Cody_Konior suggested I do have "many active ODBC connections" from legacy SSIS packages in my ETL system, so...

perhaps it's time to finally change them to OLEDB or ADO.NET versions as I wanted for some time already but posponed