chore: math lib update and type fixes (#12791)

## Description

Upgrades the math library in the repo root and find/replaces many usages of sdk.Dec, sdk.ZeroDec, sdk.OneDec, sdk.NewDec with their legacy-ified-math-lib replacements.

Note for review: I assume that I did not find 100% of usages

---

### Author Checklist

*All items are required. Please add a note to the item if the item is not applicable and
please add links to any relevant follow up issues.*

I have...

- [ ] included the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] added `!` to the type prefix if API or client breaking change
- [ ] targeted the correct branch (see [PR Targeting](https://github.com/cosmos/cosmos-sdk/blob/main/CONTRIBUTING.md#pr-targeting))
- [ ] provided a link to the relevant issue or specification
- [ ] followed the guidelines for [building modules](https://github.com/cosmos/cosmos-sdk/blob/main/docs/building-modules)
- [ ] included the necessary unit and integration [tests](https://github.com/cosmos/cosmos-sdk/blob/main/CONTRIBUTING.md#testing)
- [ ] added a changelog entry to `CHANGELOG.md`
- [ ] included comments for [documenting Go code](https://blog.golang.org/godoc)
- [ ] updated the relevant documentation or specification
- [ ] reviewed "Files changed" and left comments if necessary
- [ ] confirmed all CI checks have passed

### Reviewers Checklist

*All items are required. Please add a note if the item is not applicable and please add
your handle next to the items reviewed if you only reviewed selected items.*

I have...

- [ ] confirmed the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] confirmed `!` in the type prefix if API or client breaking change
- [ ] confirmed all author checklist items have been addressed 
- [ ] reviewed state machine logic
- [ ] reviewed API design and naming
- [ ] reviewed documentation is accurate
- [ ] reviewed tests and test coverage
- [ ] manually tested (if applicable)

client/tx/factory.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"os"
 
+	"cosmossdk.io/math"
 	"github.com/spf13/pflag"
 
 	"github.com/cosmos/cosmos-sdk/client"
@@ -259,7 +260,7 @@ func (f Factory) BuildUnsignedTx(msgs ...sdk.Msg) (client.TxBuilder, error) {
 			return nil, errors.New("cannot provide both fees and gas prices")
 		}
 
-		glDec := sdk.NewDec(int64(f.gas))
+		glDec := math.LegacyNewDec(int64(f.gas))
 
 		// Derive the fees based on the provided gas prices, where
 		// fee = ceil(gasPrice * gasLimit).