Fix[Referenda]: Use BoundedVec<u8> as field type for TrackInfo::name

[pandres95]

This PR fixes an issue that appeared after merging #2072 to stable2503, where encoding breaking changes cause issues on PJS.

[bkchr]

Why was this changed to an array and not a static Str as before?

[gui1117]

it is to be able to decode it from storage, the intention is to be able to have tracks defined in storage.

[pandres95]

Yes. That's the reason.

@gui1117 I tried changing the approach to use BoundedVec as it encodes better, but then there's the problem of needing to allocate memory while statically initializing the tracks data variables in the runtimes.

That approach requires reviving the usage of lazy_static (which I guess we don't like it very much @bkchr).

[gui1117]

it should be checked that this works with pjs, and if not we should wait for pjs to be fixed.

[gui1117]

Also this doesn't fix the fact that Tracks is a constant while at the same time intending to allow non-constant definition of tracks.
Maybe the constant metadata should be replaced with a pallet view.

[pandres95]

@gui1117 @ggwpez

I initially noticed the above committed solution (e138d56) fixed the crash in PJS apps. However, the TypeInfo wasn't matching the encoded response from the API, so the consts for referenda weren't being rendered on PJS apps.

So, I tried changing the structure to use BoundedVec as an alternative solution.

Side note This alternative implies returning to lazy_static for runtimes, since there are no viable no_std static lazy loaders in the rust library. This, at least until SyncUnsafeCell is no longer a nightly feature. Then we'll be able to use that instead of lazy_static.

The problem is mostly solved by using BoundedVec, but even though it the issue, it doesn't solve the Governance components rendering. That last problem is definitely in the hands of PJS apps.

I can propose a fix in polkadot-js/apps#11310 for the components, but using BoundedVec seems like the definitive fix.

P.S. Also calling @alindima @TarikGul who might be interested in this.

[pandres95]

@ggwpez @gui1117 @bkchr @TarikGul closed as superseed by #7671