Allow InterestsItem to be skipped on recomposition

[bentrengrove]

Fixes #73

Also adds a benchmark for topics state change to ensure this optimisation actually achieved better performance. P90+ were all improved even with a slight hit to P50 which may just be noise. This deemed this simple change worth it.

Before Change
frameDurationCpuMs   P50   4.5,   P90  14.0,   P95  17.0,   P99  25.1
frameOverrunMs   P50  -11.4,   P90   1.9,   P95   2.9,   P99  11.2

After Change
frameDurationCpuMs   P50   5.0,   P90  12.2,   P95  15.1,   P99  18.1
frameOverrunMs   P50  -11.4,   P90  -0.1,   P95   1.1,   P99   3.6

Failed experiments

Deferring the read of topics list: I also tested what would happen by deferring the read of the topics list and making it an immutable list. This would allow more to be skipped higher up the chain, specifically InterestsContent. It lead to no gain, especially when compared with the increase in code complexity this did not seem worth it.

frameDurationCpuMs   P50   4.9,   P90  12.3,   P95  15.9,   P99  18.9
frameOverrunMs   P50  -11.1,   P90  -1.4,   P95   0.3,   P99   6.9

Bottom Bar: On state change we can also see the bottom bar recomposing, this might look like an issue but fixing it via an immutable list for the top level destinations and pre-calculating the selected top destination to get the bottom bar to skip actually made a negligible difference to performance whilst greatly increasing code complexity. I deemed this change not worth it.

frameDurationCpuMs   P50   5.0,   P90  12.6,   P95  15.1,   P99  19.0
frameOverrunMs   P50  -11.4,   P90  -1.8,   P95   0.7,   P99   4.5