### Describe the bug

libraries like axios-mock-adapter define an adapter but in same cases need to access to original adapter.

It was working correctly before as the adapter was always a function.
Now it can be an array of string

Only the method getAdapter() in adapters/adapter.js can allow access to original adapters (xhr and http)
But this method is not exported a all at top level.

Can you export it ? 


### To Reproduce

Try to use axios-mock-adapter plugin with onNoMatch option

### Code snippet

_No response_

### Expected behavior

_No response_

### Axios Version

1.2.1 and upper

### Adapter Version

_No response_

### Browser

_No response_

### Browser Version

_No response_

### Node.js Version

_No response_

### OS

_No response_

### Additional Library Versions

_No response_

### Additional context/Screenshots

_No response_
index.d.ts

export type AxiosHeaderValue = AxiosHeaders | string | string[] | number | boolean | null;
interface RawAxiosHeaders {
  [key: string]: AxiosHeaderValue;
}
type MethodsHeaders = Partial<{
  [Key in Method as Lowercase<Key>]: AxiosHeaders;
} & {common: AxiosHeaders}>;
type AxiosHeaderMatcher = (this: AxiosHeaders, value: string, name: string, headers: RawAxiosHeaders) => boolean;
export class AxiosHeaders {
  constructor(
      headers?: RawAxiosHeaders | AxiosHeaders
  );
  [key: string]: any;
  set(headerName?: string, value?: AxiosHeaderValue, rewrite?: boolean | AxiosHeaderMatcher): AxiosHeaders;
  set(headers?: RawAxiosHeaders | AxiosHeaders, rewrite?: boolean): AxiosHeaders;
  get(headerName: string, parser: RegExp): RegExpExecArray | null;
  get(headerName: string, matcher?: true | AxiosHeaderMatcher): AxiosHeaderValue;
  has(header: string, matcher?: true | AxiosHeaderMatcher): boolean;
  delete(header: string | string[], matcher?: AxiosHeaderMatcher): boolean;
  clear(matcher?: AxiosHeaderMatcher): boolean;
  normalize(format: boolean): AxiosHeaders;
  concat(...targets: Array<AxiosHeaders | RawAxiosHeaders | string | undefined | null>): AxiosHeaders;
  toJSON(asStrings?: boolean): RawAxiosHeaders;
  static from(thing?: AxiosHeaders | RawAxiosHeaders | string): AxiosHeaders;
  static accessor(header: string | string[]): AxiosHeaders;
  static concat(...targets: Array<AxiosHeaders | RawAxiosHeaders | string | undefined | null>): AxiosHeaders;
  setContentType(value: ContentType, rewrite?: boolean | AxiosHeaderMatcher): AxiosHeaders;
  getContentType(parser?: RegExp): RegExpExecArray | null;
  getContentType(matcher?: AxiosHeaderMatcher): AxiosHeaderValue;
  hasContentType(matcher?: AxiosHeaderMatcher): boolean;
  setContentLength(value: AxiosHeaderValue, rewrite?: boolean | AxiosHeaderMatcher): AxiosHeaders;
  getContentLength(parser?: RegExp): RegExpExecArray | null;
  getContentLength(matcher?: AxiosHeaderMatcher): AxiosHeaderValue;
  hasContentLength(matc