in_tail: Expand glob capability for square brackets and one character matcher

[cosmo0920]

Which issue(s) this PR fixes: This PR will fix none of the issue but this was raised in community slack channel.

What this PR does / why we need it:

This feature was requested on the community slack's #fluentd channel. For now, we didn't support for square brackets pattern and one character matcher in #expand_paths.

This shouldn't be fit for the following case.

The logs are named as follows:

.
├── 01.log
├── 02.log
├── 03.log
├── 12.log
├── 13.log
├── 20.log

Then, a user wants to tail 02.log, 03.log, 12.log, and 13.log, and excluding to tail 01.log and 20.log with the following configuration:

<source>
  @type tail
  path "[0-1][2-3].log"
  <parse>
    @type none
  </parse>
  tag log.test
  read_from_head
  use_extended_glob # To use this expansion, users need to enable this feature explicitly.
</source>

However, the current Fluentd doesn't handle the "[0-1][2-3].log" pattern as glob. It just handles as normal file name. This shouldn't be effective for this use case.

It would be nice to handle this pattern on the in_tail plugin.

Docs Changes: https://github.com/fluent/fluentd-docs-gitbook/pull/488

Release Note: Same as title.