Add a way to get content without URL encoding query params

[0xDagal]

Is your feature request related to a problem? Please describe.
I try to request a page by its title, but it has space in it so this title spaces are translated to "+" by Confluence which is URL encoded to "%2B" by the SDK, but the API does not understand it.

https://my-confluence-instance.lan/rest/api/content?title=My+Page => ok
https://my-confluence-instance.lan/rest/api/content?title=My%2BPage => nok

Describe the solution you'd like
Add a parameter in GetContent to tell it to URL encode the params or just "stringify" it. I will send a PR for that.

Describe alternatives you've considered
To make it work for my needs, I chained directly the params with a simple fmt.Sprintf and put it in the url.URL.RawQuery

Additional context
From my Confluence instance manifest:

<version>8.5.14</version>
<buildNumber>19243</buildNumber>
<applinksVersion>9.1.8</applinksVersion>