[BUG]Four problems were found in the module mssql.py

Description
Three problems were found in the module mssql.py

1. Lack of quote identifier for MSSQL keyword
2. Database connection is not closed in time. Once saltstack initiates too many connections to MSSQL database, it will affect the database
3. There is no escape for Python special characters, for example, the tsql_query function will have problems when special characters are encountered
4. Added the autocommit property to True when getting the database connection.

Setup
(Please provide relevant configs and/or SLS files (be sure to remove sensitive info).

Steps to Reproduce the behavior
(Include debug logs if possible and relevant)

Expected behavior
A clear and concise description of what you expected to happen.

Screenshots
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Versions Report

Salt Version:
           Salt: 3000
 
Dependency Versions:
           cffi: 1.12.2
       cherrypy: Not Installed
       dateutil: 2.7.5
      docker-py: Not Installed
          gitdb: Not Installed
      gitpython: Not Installed
         Jinja2: 2.10
        libgit2: Not Installed
       M2Crypto: Not Installed
           Mako: Not Installed
   msgpack-pure: Not Installed
 msgpack-python: 0.6.2
   mysql-python: Not Installed
      pycparser: 2.19
       pycrypto: 2.6.1
   pycryptodome: Not Installed
         pygit2: Not Installed
         Python: 2.7.5 (default, Nov  6 2016, 00:28:07)
   python-gnupg: Not Installed
         PyYAML: 3.11
          PyZMQ: 15.3.0
          smmap: Not Installed
        timelib: Not Installed
        Tornado: 4.5.3
            ZMQ: 4.1.4

Additional context
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Start with mssql.py and trace the tsql_query function and database-connection handling. Review the four reported concerns: MSSQL identifier quoting, timely connection closure, escaping Python special characters, and the autocommit setting. Done means these behaviors are addressed and the MSSQL module operates correctly for the reported cases.