JSF / Web UI migration - Fix timing discrepancy between reports and tags

Launch a JSF migration

• In the previous migrations list and in the report the current user's time is shown (including for tag names)
• Going to branch management or releases and tags screen the UTC time is used to create actual branch for the migration and tags

=> e.g. if I do a migration at 9h22 paris time, reports show 9H22 and tags / branch name is actually 8H22

Expected: name / time should be consistent everywhere (no particular preference, just a matter of consistency). As Miguel indicated, UTC could be a good choice for teams that work in different timezones.