Make staff cards more responsive on mobile

[mark-a-wilson]

UI enhancement Fixes #58

Modified markup of PersonnelCardViewComponent and added new styles so that on phones, staff cards:

• take up less vertical space in the viewport
• have bigger social media icons which are spaced further apart

[parulmishra]

SonarQube Analysis: https://sonarqube-ifttgq-tools.pathfinder.gov.bc.ca/dashboard?id=BCDevExchange-PR-59