Issue 375: For EventRecords, rename device property and finish computer property removal

[ajnelson-nist]

This Pull Request resolves remaining requirements of Issue #375 .

Coordination

• [x] Pull Request is against correct branch
• [x] Pull Request is in, or reverted to, Draft status before Solutions Approval vote has passed. *(N/A, but keeping in Draft until external examples are reviewed.)
• [x] CI passes in UCO feature branch
• [x] CI passes in UCO current unstable branch (c337a62)
• [x] CI passes in CASE current unstable branch tracking UCO's unstable as submodule (d8e81a7)
• [x] Impact on SHACL validation reviewed for CASE-Examples
• [x] Impact on SHACL validation remediated for CASE-Examples (N/A - observable:device was not used)
• [x] Impact on SHACL validation reviewed for casework.github.io
• [x] Impact on SHACL validation remediated for casework.github.io (N/A - observable:device was not used)
• [x] Milestone linked
• [x] Solutions Approval vote logged on corresponding Issue (once logged, can be taken out of Draft PR status) (N/A, but keeping in Draft until external examples are reviewed)

[ajnelson-nist]

@b0bkaT , once CI passes in the checklist items, this is good for your review and merge.