Upgrade Cosmos SDK to v0.45

[youngjoon-lee]

Today, the cosmos-sdk v0.44.0 was released.
https://github.com/cosmos/cosmos-sdk/releases/tag/v0.44.0

They are saying that all chains should upgrade cosmos-sdk to v0.44, regardless of whether their version is v0.42 or v0.43.

[gyuguen]

Oops, it's a mandatory update. 😢

[youngjoon-lee]

Yeah. I haven't read the release note seriously, but it looks mandatory.

[youngjoon-lee]

I just promoted the target version from v0.44 to v0.46 because v0.46 is going to have a x/nft module which is a standard for IBC.
From Cosmos Discord, the x/nft is already ready-to-use but will be released as v0.46.
https://discord.com/channels/669268347736686612/903696998874632282/951746679810428950
One of options for us is backporting the x/nft to panacea-core which is currently using cosmos-sdk v0.42.x, but it would be a tough work since v0.45~46 have a lot of breaking changes. Instead of backporting, it would be better to consider upgrading cosmos-sdk to v0.46 directly. Now, only v0.46.0-beta2 was released but it seems that v0.46.0 will be released in 19 days according to their milestone: https://github.com/cosmos/cosmos-sdk/milestone/46.

[0xHansLee]

The cosmos-sdk has been upgraded to v0.45.4, #356.

[youngjoon-lee]

Done as #221 (comment). I just renamed the issue title to ... v0.45.