Covid level text update

This MR updates the Covid level text.

The strings marked like this mean they can be variables instead of hardcoded text:

• Red - 4:

  • "Warning: the current CERN COVID Scale is Red - 4. There is a strong risk that asymptomatic or pre-symptomatic infected individuals circulate within the CERN site. There may be around 4’000 daily on-site accesses during this stage. Please reduce the value below the threshold of 5%. See with your supervisor, DSO/LEXGLIMOS and space manager if this scenario is acceptable and if any additional measures are required."

• Orange - 3:

  • "Warning: the current CERN COVID Scale is Orange - 3. There is a medium risk that asymptomatic or pre-symptomatic infected individuals circulate within the CERN site. There may be around 5’000 daily on-site accesses during this stage. See with your supervisor, DSO/LEXGLIMOS and space manager if this scenario is acceptable and if any additional measures can be applied (ALARA)."

• Yellow - 2:

  • "Note: the current CERN COVID Scale is Yellow - 2. There is a reduced risk that asymptomatic or pre-symptomatic infected individuals circulate within the CERN site. There may be around 6’500 daily on-site accesses during this stage. See with your supervisor, DSO/LEXGLIMOS and space manager if this scenario is acceptable and if any additional measures can be applied (ALARA)."

• Green - 1:

  • "Note: the current CERN COVID Scale is Green – 1. The risk of circulation of asymptomatic or pre-symptomatic infected individuals within the CERN site is considered negligible. There may be more than 8’000 daily on-site accesses. Align your risk assessment with the guidance and instructions provided by the HSE Unit."