Switch to Ampersands to Separate Query Parameters

[Jason Boyer]

Affects Evergreen master

This is a combination of 3 prior bugs because attempts to address things piecemeal have left things in various states of brokenness.

Re: bug 1687545, to use ampersands rather than semicolons we can make a simple change to our local copy of the TemplateToolkit CGI plugin. Branch https://git.evergreen-ils.org/?p=working/Evergreen.git;a=shortlog;h=refs/heads/user/jboyer/lp1687545_chicago_handshake / working/user/jboyer/lp1687545_chicago_handshake does this.

Re: bug 1914116, the above does replace all semicolons with a plain ampersand, leaving us with invalid html. This can be fixed in the general case by applying the TT html filter in the mkurl block rather than applying the filter everywhere that mkurl is used. Branch https://git.evergreen-ils.org/?p=working/Evergreen.git;a=shortlog;h=refs/heads/user/jboyer/lp1914116_html_filter / working/user/jboyer/lp1914116_html_filter does this.

Applying the above two branches works as expected except for those times where a "came from" / "return to" type of parameter is used, such as when placing holds. In that case those query params are multiple-encoded usually leading to an internal server error, as reported in bug 1918470 .

Because of the timing of the above the first 2 branches were briefly applied to master and made it into the 3.5.3 and 3.6.2 point releases, leading to the issues described in bug 1918470. They were both removed until a whole fix can be applied without also breaking holds.

Ideally this can be addressed by making it possible to tell mkurl that you want it to return a value run through the html filter (default), uri, or none at all.