Advanced Membering Ordering in Members page

[j-hariharan]

Currently, ordering of core members depending on seniority of core post is done based on a hard-coded array. This approach is not optimal, especially considering we already have a schema for core posts already, so it would be good to use that for priority as well.

There is also an issue. Even when a specific SIG is selected, the members of the main core who are also part of that SIG show up higher than the specific SIG core, which is not ideal. This has to be fixed such that SIG core is given priority when the filter for a specific SIG is selected.