Revert commit that modified OCRepresentation and AttribueValue

Revert commit that modified OCRepresentation and AttribueValue

The commit for [IOT-1583] had several unseen concequnces and
should not be on the 1.3-rel branch.

This change reverts that commit as well as two commits
that were made in responce to that commit.

Revert "resource: Avoid to expose internal headers"
This reverts commit 6303c498fcebe1304983e5a650e5e6ec712e0cab.

Revert "[IOT-2251] Resolve getValue() & setValue() APIs for argument string, Attribute Value"
This reverts commit 05671f38527acd30ff5a761b3c0a7cde933a0b17.

Revert "IOT-1583: Fixing /W3 warnings in /resource directory - part 5."
This reverts commit 924a7f267298aafc379ee0fa62871724e8afce19.

See also the following bugs
Bug: https://jira.iotivity.org/browse/IOT-2233
Bug: https://jira.iotivity.org/browse/IOT-2251
Bug: https://jira.iotivity.org/browse/IOT-2277
Bug: https://jira.iotivity.org/browse/IOT-1583
Bug: https://jira.iotivity.org/browse/IOT-2254

Change-Id: I6ca8fad887ff7a17a0bceacfe0ba2147d64c9394
Signed-off-by: George Nash <george.nash@intel.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/20007
Reviewed-by: Dan Mihai <Daniel.Mihai@microsoft.com>
Tested-by: Dan Mihai <Daniel.Mihai@microsoft.com>