improvement(driver-utils): enable noUncheckedIndexedAccess

[RishhiB]

• enable noUncheckedIndexAccess

// Total: 12 errors in 4 files

// File: src/adapters/compression/summaryblob/documentStorageServiceSummaryBlobCompressionAdapter.ts
// 3 errors:
Line 66: error TS18048: 'firstByte' is possibly 'undefined'.
  return (firstByte & 0xf0) === 0xb0;
         ~~~~~~~~~

Line 77: error TS2532: Object is possibly 'undefined'.
  IsoBuffer.from(blob)[0] & 0x0f;
  ~~~~~~~~~~~~~~~~~~~~~~~

Line 93: error TS18048: 'firstByte' is possibly 'undefined'.
  if ((firstByte & 0xf0) !== 0xb0) {
      ~~~~~~~~~

// File: src/insecureUrlResolver.ts
// 3 errors:
Line 57: error TS2345: Argument of type 'string | undefined' is not assignable to parameter of type 'string | null'.
  return this.resolveHelper(documentId, relativePath, parsedUrl.search);
                           ~~~~~~~~~~

Line 61: error TS18048: 'documentId' is possibly 'undefined'.
  const documentRelativePath = fullPath.slice(documentId.length);
                                             ~~~~~~~~~~

Line 62: error TS2345: Argument of type 'string | undefined' is not assignable to parameter of type 'string | null'.
  return this.resolveHelper(documentId, documentRelativePath);
                           ~~~~~~~~~~

// File: src/parallelRequests.ts
// 4 errors:
Line 598: error TS2532: Object is possibly 'undefined'.
  assert(deltas[0].sequenceNumber === fromTotal, 0x26d /* "wrong start" */);
         ~~~~~~~~~

Line 600: error TS2532: Object is possibly 'undefined'.
  assert(deltas[0].sequenceNumber === lastFetch + 1, 0x26e /* "wrong start" */);
         ~~~~~~~~~

Line 602: error TS2532: Object is possibly 'undefined'.
  lastFetch = deltas[deltas.length - 1].sequenceNumber;
             ~~~~~~~~~~~~~~~~~~~~~~~~~

Line 604: error TS2532: Object is possibly 'undefined'.
  lastFetch - deltas[0].sequenceNumber + 1 === deltas.length,
              ~~~~~~~~~

// File: src/protocol/gitHelper.ts
// 2 errors:
Line 87: error TS18048: 'node' is possibly 'undefined'.
  node.trees[decodeURIComponent(entryPathBase)] = newTree;
  ~~~~

Line 90: error TS18048: 'node' is possibly 'undefined'.
  node.blobs[decodeURIComponent(entryPathBase)] = entry.sha;
  ~~~~

[jason-ha]

build is failing - adding comment to clear review requested