fix: various fixes and features for u15 (#9251)

refs: #9224

## Description

Upgrade our cosmos-sdk fork and cosmos/iavl to pick up bug fixes and
features.

### Security Considerations

See upgrade-15 notes.

### Scaling Considerations

N/A

### Documentation Considerations

N/A - internal changes

### Testing Considerations

See upgrade-15 notes.

### Upgrade Considerations

N/A

golang/cosmos/go.mod

@@ -186,7 +186,10 @@ replace (
 // Agoric-specific replacements:
 replace (
 	// We need a fork of cosmos-sdk until all of the differences are merged.
-	github.com/cosmos/cosmos-sdk => github.com/agoric-labs/cosmos-sdk v0.46.16-alpha.agoric.2.1
+	github.com/cosmos/cosmos-sdk => github.com/agoric-labs/cosmos-sdk v0.46.16-alpha.agoric.2.3
+
+	// Pick up an IAVL race fix.
+	github.com/cosmos/iavl => github.com/cosmos/iavl v0.19.7
 
 	// use cometbft
 	// Use our fork at least until post-v0.34.14 is released with

golang/cosmos/go.sum

@@ -232,8 +232,8 @@ github.com/aead/siphash v1.0.1/go.mod h1:Nywa3cDsYNNK3gaciGTWPwHt0wlpNV15vwmswBA
 github.com/afex/hystrix-go v0.0.0-20180502004556-fa1af6a1f4f5/go.mod h1:SkGFH1ia65gfNATL8TAiHDNxPzPdmEL5uirI2Uyuz6c=
 github.com/agoric-labs/cometbft v0.34.30-alpha.agoric.1 h1:tqCNL72pQXdUmBzgv1md5SN2U3K/PaYQ4qZ5pFv8v6w=
 github.com/agoric-labs/cometbft v0.34.30-alpha.agoric.1/go.mod h1:myvkihZD8eg9jKE3WFaugkNoL5nvEqlP7Jbjg98pCek=
-github.com/agoric-labs/cosmos-sdk v0.46.16-alpha.agoric.2.1 h1:VZFX9Mogwt4cVTnkdt9zA6UJue4XYXdBURNhlTWw71Q=
-github.com/agoric-labs/cosmos-sdk v0.46.16-alpha.agoric.2.1/go.mod h1:zUe5lsg/X7SeSO1nGkzOh9EGKO295szfrxIxYmeLYic=
+github.com/agoric-labs/cosmos-sdk v0.46.16-alpha.agoric.2.3 h1:EpuIGO5/l8Hwdo6BhRCvETys6HrFvDBbbtarT9L+gKg=
+github.com/agoric-labs/cosmos-sdk v0.46.16-alpha.agoric.2.3/go.mod h1:d7e4h+w7FNBNmE6ysp6duBVuQg67pqMtvsLwpT9ca3E=
 github.com/agoric-labs/cosmos-sdk/ics23/go v0.8.0-alpha.agoric.1 h1:2jvHI/2d+psWAZy6FQ0vXJCHUtfU3ZbbW+pQFL04arQ=
 github.com/agoric-labs/cosmos-sdk/ics23/go v0.8.0-alpha.agoric.1/go.mod h1:E45NqnlpxGnpfTWL/xauN7MRwEE28T4Dd4uraToOaKg=
 github.com/ajstarks/svgo v0.0.0-20180226025133-644b8db467af/go.mod h1:K08gAheRH3/J6wwsYMMT4xOr94bZjxIelGM0+d/wbFw=
@@ -376,8 +376,8 @@ github.com/cosmos/go-bip39 v1.0.0 h1:pcomnQdrdH22njcAatO0yWojsUnCO3y2tNoV1cb6hHY
 github.com/cosmos/go-bip39 v1.0.0/go.mod h1:RNJv0H/pOIVgxw6KS7QeX2a0Uo0aKUlfhZ4xuwvCdJw=
 github.com/cosmos/gorocksdb v1.2.0 h1:d0l3jJG8M4hBouIZq0mDUHZ+zjOx044J3nGRskwTb4Y=
 github.com/cosmos/gorocksdb v1.2.0/go.mod h1:aaKvKItm514hKfNJpUJXnnOWeBnk2GL4+Qw9NHizILw=
-github.com/cosmos/iavl v0.19.6 h1:XY78yEeNPrEYyNCKlqr9chrwoeSDJ0bV2VjocTk//OU=
-github.com/cosmos/iavl v0.19.6/go.mod h1:X9PKD3J0iFxdmgNLa7b2LYWdsGd90ToV5cAONApkEPw=
+github.com/cosmos/iavl v0.19.7 h1:ij32FaEnwxfEurtK0QKDNhTWFnz6NUmrI5gky/WnoY0=
+github.com/cosmos/iavl v0.19.7/go.mod h1:X9PKD3J0iFxdmgNLa7b2LYWdsGd90ToV5cAONApkEPw=
 github.com/cosmos/ibc-go/v6 v6.2.1 h1:NiaDXTRhKwf3n9kELD4VRIe5zby1yk1jBvaz9tXTQ6k=
 github.com/cosmos/ibc-go/v6 v6.2.1/go.mod h1:XLsARy4Y7+GtAqzMcxNdlQf6lx+ti1e8KcMGv5NIK7A=
 github.com/cosmos/keyring v1.2.0 h1:8C1lBP9xhImmIabyXW4c3vFjjLiBdGCmfLUfeZlV1Yo=