Network details: remove font tag from field value

Embedded HTML is not supported in detail view results,
so remove embedded font tag to prevent the tag characters from being displayed.
UI > Instance Wizard > Step 4 > correct label from "Data Disk Offering" to "Disk Offering" since selected disk offering here refers to root disk volume when selected template is of ISO format, data disk volume otherwise.
CLOUDSTACK-4950: fix the problem to support sessions to multiple vCenter instance