ini_file - support optional spaces around section names (#8075)

* ini_file - support optional spaces between section names and their surrounding brackets

Some ini files have spaces between some of their section names and the
brackets that enclose them. This is documented in the 'openssl.cnf(5)' man
page. In order to manage files such as /etc/ssl/openssl.cnf with ini_file
before now, one would have to include spaces in the section name like this:
    section: ' crypto_policy '
    option: Options
    value: UnsafeLegacyRenegotiation

This change implements matching section headers with such optional spaces.
Existing tasks using the workaround above will continue to work, even in
cases where spaces in section headers are subsequently removed.

* readability improvement in the test content expressions

---------

Co-authored-by: Todd Lewis <todd_lewis@unc.edu>

plugins/modules/ini_file.py

@@ -304,9 +304,11 @@ def do_ini(module, filename, section=None, option=None, values=None,
     before = after = []
     section_lines = []
 
+    section_pattern = re.compile(to_text(r'^\[\s*%s\s*]' % re.escape(section.strip())))
+
     for index, line in enumerate(ini_lines):
         # find start and end of section
-        if line.startswith(u'[%s]' % section):
+        if section_pattern.match(line):
             within_section = True
             section_start = index
         elif line.startswith(u'['):