Redefine sesitive accounts for more clarity and update "important partners" in DEFENDDER2.3v1 to "Key suppliers and Partners" as stated in the portal

[ahuynhECS]

🗣 Description

It was noted that the sensitive user definition was too broad for a user to easily define. The definition found in the key terminology section was updated to match that of priority accounts as recommended by Microsoft. DEFENDER2.3v1 also notes important partners in the policy and this has been updated to match terminology in the admin center.

💭 Motivation and context

Change required to expand on the definition of sensitive users and for DEFENDER2.3v1 to match terminology used in the admin center.

closes #1838

🧪 Testing

N/A baseline cahnge

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