Rename actuator field to profile (issue #398)

[dlemire60]

Addresses issue #398. I reviewed this on 8/18/2022 and have no comments. Will continue to observe if / as more commits are added.

[Vasileios-Mavroeidis]

The changes look correct and accurate based on what we have discussed.

Language recommendation: Actuator Profile: "An OpenC2 Specification that defines a category...."

[dlemire60]

This issue also relates to Architecture Specification Issue 67, and a complementary PR will likely be needed for the Architecture Specification once this change is finalized.

[dlemire60]

Presented at the 8/24/2022 working meeting. Notes:

• @dlemire60 suggested that the Actuator Profile definition should emphasize the functional content, not the document, and agreed to propose an updated definition.
• @davaya will add a definition for Actuator Profile Identifier to the glossary, since that term is introduced in new text in this PR
• Patrick Maroney asked about the remove of a MUST from (old numbering) lines 869-870; @davaya explained that the MUST was implicit in the way the property tables specify the language and so having it in text seemed superfluous.
• The change from actuator to profile in the message (new line 1178) is the heart of the breaking change
• The list of APs in section 3.3.1.3 is the normative list; the text also points to the registry in the Architecture Spec repo but this normative list in the LS aligns with @sparrell's preference to capture this in the LS and publish an updated version when the list changes.

[dlemire60]

Approved for merging at the 7 September 2022 working meeting.