revert: swaps new slippage modal (#25394)

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## **Description**

Reverts #25124

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## **Related issues**

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Fixes: https://consensyssoftware.atlassian.net/browse/SWAPS-3428
 
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> [!NOTE]
> **Medium Risk**
> Medium risk because it changes the Bridge slippage configuration UX
and navigation targets, removing the custom/default slippage modal flow
and associated validation/controls which could impact users’ ability to
set slippage correctly.
> 
> **Overview**
> Reverts the newer Bridge slippage UI by deleting the `InputStepper`
component (and its snapshots/tests) and removing the
`DefaultSlippageModal`, `CustomSlippageModal`, and
`DefaultSlippageButtonGroup` implementations and tests.
> 
> Updates `QuoteDetailsCard` to navigate to
`Routes.BRIDGE.MODALS.SLIPPAGE_MODAL` (dropping the previous
`DEFAULT_SLIPPAGE_MODAL` + `network` params), and adds new
`SlippageModal` styling/types plus a focused `SlippageModal.test.tsx` to
cover option selection and applying (dispatching `setSlippage`).
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
e691a98. This will update automatically
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Author: GeorgeGkas