Front-end changes to subtracks

[Oanh-and-only-Oanh]

Remove subtrack dropdown filter on challenge listings page

Remove subtrack abbreviations on challenge listings page

[lakshmiathreya]

cc @SathyaJayabal

[SathyaJayabal]

@Oanh-and-only-Oanh , how about the updates to the member profile pages and the stats history.

cc @lakshmiathreya @sushilshinde

Without subtracks will the member ratings for different subtracks be calculated properly ?
Same question regarding stats for the different subtracks ?

[Oanh-and-only-Oanh]

That's a good question and I think we need @rootelement to help answer.
cc @mtwomey

[sushilshinde]

Part 1: Listing Page Change: #4706

Part 2: Details Page Change: #4709