Convert stragging BN type imports (#3595)

packages/types/src/codec/Compact.ts

@@ -1,12 +1,11 @@
 // Copyright 2017-2021 @polkadot/types authors & contributors
 // SPDX-License-Identifier: Apache-2.0
 
+import type BN from 'bn.js';
 import type { CodecHash, Hash } from '../interfaces';
 import type { AnyJson, AnyNumber, Constructor, ICompact, InterfaceTypes, Registry } from '../types';
 import type { CompactEncodable } from './types';
 
-import BN from 'bn.js';
-
 import { compactFromU8a, compactToU8a, isBigInt, isBn, isNumber, isString } from '@polkadot/util';
 
 import { typeToConstructor } from './utils';

packages/types/src/ethereum/LookupSource.ts

@@ -1,10 +1,9 @@
 // Copyright 2017-2021 @polkadot/types authors & contributors
 // SPDX-License-Identifier: Apache-2.0
 
+import type BN from 'bn.js';
 import type { Registry } from '../types';
 
-import BN from 'bn.js';
-
 import { isBigInt, isBn, isHex, isNumber, isU8a, u8aConcat, u8aToBn, u8aToHex, u8aToU8a } from '@polkadot/util';
 import { decodeAddress } from '@polkadot/util-crypto';
 

packages/types/src/extrinsic/ExtrinsicEra.ts

@@ -1,10 +1,9 @@
 // Copyright 2017-2021 @polkadot/types authors & contributors
 // SPDX-License-Identifier: Apache-2.0
 
+import type BN from 'bn.js';
 import type { AnyU8a, IExtrinsicEra, Registry } from '../types';
 
-import BN from 'bn.js';
-
 import { assert, bnToBn, formatNumber, hexToU8a, isHex, isObject, isU8a, u8aToBn, u8aToU8a } from '@polkadot/util';
 
 import { Enum } from '../codec/Enum';

packages/types/src/generic/LookupSource.ts

@@ -1,10 +1,9 @@
 // Copyright 2017-2021 @polkadot/types authors & contributors
 // SPDX-License-Identifier: Apache-2.0
 
+import type BN from 'bn.js';
 import type { Registry } from '../types';
 
-import BN from 'bn.js';
-
 import { isBigInt, isBn, isHex, isNumber, isU8a, u8aConcat, u8aToBn, u8aToHex, u8aToU8a } from '@polkadot/util';
 import { decodeAddress } from '@polkadot/util-crypto';