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
{
    if (IsArgNegated(arg)) return fs::path{};
    std::string path_str = GetArg(arg, "");
    if (path_str.empty()) return default_value;
    fs::path result = fs::PathFromString(path_str).lexically_normal();
    
    return result.has_filename() ? result : result.parent_path();
}
const fs::path& ArgsManager::GetBlocksDirPath() const
{
    LOCK(cs_args);
    fs::path& path = m_cached_blocks_path;
    
    
    if (!path.empty()) return path;
    if (IsArgSet("-blocksdir")) {
        path = fs::absolute(GetPathArg("-blocksdir"));
        if (!fs::is_directory(path)) {
            path = "";
            return path;
        }
    } else {
        path = GetDataDirBase();
    }
    path /= fs::PathFromString(BaseParams().DataDir());
    path /= "blocks";
    fs::create_directories(path);
    return path;
}
const fs::path& ArgsManager::GetDataDir(bool net_specific) const