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
for (const std::string& socket_addr : args.GetArgs("-bind")) {
        std::string host_out;
        uint16_t port_out{0};
        std::string bind_socket_addr = socket_addr.substr(0, socket_addr.rfind('='));
        if (!SplitHostPort(bind_socket_addr, port_out, host_out)) {
            return InitError(InvalidPortErrMsg("-bind", socket_addr));
        }
    }
     
    std::vector<std::string> uacomments;
    for (const std::string& cmt : args.GetArgs("-uacomment")) {
        if (cmt != SanitizeString(cmt, SAFE_CHARS_UA_COMMENT))
            return InitError(strprintf(_("User Agent comment (%s) contains unsafe characters."), cmt));
        uacomments.push_back(cmt);
    }
    strSubVersion = FormatSubVersion(CLIENT_NAME, CLIENT_VERSION, uacomments);
    if (strSubVersion.size() > MAX_SUBVERSION_LENGTH) {
        return InitError(strprintf(_("Total length of network version string (%i) exceeds maximum length (%i). Reduce the number or size of uacomments."),
            strSubVersion.size(), MAX_SUBVERSION_LENGTH));
    }
    if (args.IsArgSet("-onlynet")) {
        std::set<enum Network> nets;
        for (const std::string& snet : args.GetArgs("-onlynet")) {
            enum Network net = ParseNetwork(snet);
            if (net == NET_UNROUTABLE)
                return InitError(strprintf(_("Unknown network specified in -onlynet: '%s'"), snet));
            nets.insert(net);
        }
        for (int n = 0; n < NET_MAX; n++) {
            enum Network net = (enum Network)n;