The `make install` script, which most users would run via `sudo` to install into `/usr/local`, will use the current umask of the root user when creating certain files and directories. If one uses a restrictive umask by default (e.g. `umask 077`), this means that only the root user will be able to use the full Bitcoin package.

**Expected behavior**

The install script creates all directories and files, including man pages, etc., with permissions `644` / `755`.

**Actual behavior**

Certain folders are created using the default umask, e.g.:

- /usr/local/share/man/man1/
- /usr/local/lib/pkgconfig/
- [...]

This means that only root can access files in these folders and other users won't be able to read the man pages (for example).

**To reproduce**

```bash
$ ./autogen.sh
$ make
$ sudo -iu root
% umask 077
% make install
```

**System information**

OS: Linux
bitcoind version: HEAD
const Reply& reply = SendRequestAndGetReply(
            *sock,
            strprintf("SESSION CREATE STYLE=STREAM ID=%s DESTINATION=TRANSIENT SIGNATURE_TYPE=7", session_id));
        m_private_key = DecodeI2PBase64(reply.Get("DESTINATION"));
    } else {
        
        
        const auto& [read_ok, data] = ReadBinaryFile(m_private_key_file);
        if (read_ok) {
            m_private_key.assign(data.begin(), data.end());
        } else {
            GenerateAndSavePrivateKey(*sock);
        }
        const std::string& private_key_b64 = SwapBase64(EncodeBase64(m_private_key));
        SendRequestAndGetReply(*sock,
                               strprintf("SESSION CREATE STYLE=STREAM ID=%s DESTINATION=%s",
                                         session_id,
                                         private_key_b64));
    }
    m_my_addr = CService(DestBinToAddr(MyDestination()), I2P_SAM31_PORT);
    m_session_id = session_id;
    m_control_sock = std::move(sock);
    Log("%s SAM session %s created, my address=%s",
        Capitalize(session_type),
        m_session_id,
        m_my_addr.ToString());
}
std::unique_ptr<Sock> Session::StreamAccept()