Restore URC string when using generic URC callback

[ActoryOu]

• Restore URC string for generic URC callback for users to differentiate URC token.
• Add an unit-test case to test URC with colon but the token is not in the table.

[chinglee-iot]

@paulbartell Thanks for your feedback. I also review current test cases for URC handling.

This PR fix the following scenario

• _Cellular_HandlePacket( &context, AT_UNSOLICITED, CELLULAR_AT_MULTI_DATA_WO_PREFIX_STRING_RESP );
  • Input URC is "+QIRD: 32\r123243154354364576587utrhfgdghfg".
  • Generic URC handler should be called. This PR restore the input string to generic URC handler. The input string passed to generic handler before this PR is "32\r123243154354364576587utrhfgdghfg" and after this PR is "+QIRD: 32\r123243154354364576587utrhfgdghfg". This input string is also compared in _CMOCK_Cellular_Generic_CALLBACK.

The followings are existing test cases related to URC handler Invalid input test

• _Cellular_HandlePacket( &context, AT_UNSOLICITED, NULL );
  • CELLULAR_PKT_STATUS_BAD_PARAM should be returned if token string is NULL
• _Cellular_HandlePacket( &context, AT_UNSOLICITED, CELLULAR_PLUS_TOKEN_ONLY_STRING );
  • CELLULAR_PKT_STATUS_BAD_REQUEST should be returned if token string is "+"
• _Cellular_HandlePacket( &context, AT_UNSOLICITED, CELLULAR_SAMPLE_PREFIX_STRING_LARGE_INPUT );
  • CELLULAR_PKT_STATUS_FAILURE should be returned if token string is longer than CELLULAR_AT_MAX_STRING_SIZE
• _Cellular_HandlePacket( &context, AT_UNSOLICITED, CELLULAR_URC_TOKEN_STRING_INPUT );
  • CELLULAR_PKT_STATUS_FAILURE should be returned if the token string handler function is NULL

URC token table test

• _Cellular_HandlePacket( &context, AT_UNSOLICITED, CELLULAR_URC_TOKEN_STRING_INPUT_START_PLUS ); Updated
  • Happy path test. The URC token is handled in URC token table. Only token after ":" should be returned. The token is compared. In this case, the passed token is zero length string.

Generic URC handler test

• _Cellular_HandlePacket( &context, AT_UNSOLICITED, CELLULAR_URC_TOKEN_STRING_GREATER_INPUT ); Updated
  • "RDY" is registered in URC handler table. Input URC is "RDYY". Generic URC handler should be called. "RDYY" is also compared in generic URC handler.
• _Cellular_HandlePacket( &context, AT_UNSOLICITED, CELLULAR_URC_TOKEN_STRING_SMALLER_INPUT ); Updated
  • "RDY" is registered in URC handler table. Input URC is "RD". Generic URC handler should be called. "RD" is also compared in generic URC handler.

If more test cases are required, please also share your suggestion to us.