Add utils for persisted state migration from old extension

[lukaw3d]

Functions for migrating state from https://github.com/oasisprotocol/oasis-wallet-ext

[github-actions]

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[codecov]

Codecov Report

Merging #1771 (a4a1fc5) into master (0f0b432) will increase coverage by 0.36%.
The diff coverage is 90.54%.

❗ Current head a4a1fc5 differs from pull request most recent head 67f4482. Consider uploading reports for the commit 67f4482 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1771      +/-   ##
==========================================
+ Coverage   82.02%   82.39%   +0.36%     
==========================================
  Files         187      187              
  Lines        4885     4953      +68     
  Branches      897      912      +15     
==========================================
+ Hits         4007     4081      +74     
+ Misses        878      872       -6     

Flag	Coverage Δ
cypress	47.53% <100.00%> (-0.04%)	⬇️
jest	78.15% <90.54%> (+0.42%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
src/app/components/LanguageSelect/index.tsx	72.72% <100.00%> (-1.19%)	⬇️
src/locales/i18n.ts	100.00% <100.00%> (ø)
src/utils/__fixtures__/test-inputs.ts	100.00% <100.00%> (+100.00%)	⬆️
src/utils/walletExtensionV0.ts	89.70% <89.70%> (ø)

... and 5 files with indirect coverage changes

[lubej]

Overall looks good to me, would wait for @buberdds approval, as he is more familiar with the codebase.

[lubej]

Would be nice to have type as an enum, as it can easily be mistyped.

[lukaw3d]

The string literal also forces correct spelling everywhere, similar to an enum

and correctly narrows down the type later, so account fields specific to WALLET_INSIDE become available:

        if (acc.type === 'WALLET_INSIDE') {
          return {
            publicKey: acc.publicKey,
            address: acc.address,
            type: WalletType.Mnemonic,
            path: [44, 474, acc.hdPath],
            pathDisplay: `m/44'/474'/${acc.hdPath}'`,
            privateKey: acc.privateKey,
            balance: {
              available: null,
              debonding: null,
              delegations: null,
              total: null,
            },
            name: acc.accountName,
          }
        }