Add required columns to 'Manage Events/Sessions' for rating

[shreyanshdwivedi]

Sub-issue of #2959

We give any role that has the right to rate

• the option to choose any star from 1 to 5

Also then we can have two more column showing

• average rating
• number of people who rated

Columns Required - | Rate session | Avg Rating | No. of people rated |

Additional Context
On it

[kushthedude]

@shreyanshdwivedi I suggest you take this following feature on hold, Ember-Table refactor for Manage-Events will be ready in 2-3 days, I don't think we should at least, for now, make a change in manage-events model table, What you say ?

[shreyanshdwivedi]

If @CosmicCoder96 feels the same, I can put a hold on it.

[abhinavk96]

@shreyanshdwivedi If you are creating a separate cell component, then you can just go ahead, I am using the existing cell-components.