Add templates for additional tools (Iteration 1)

[mcguinlu]

This is a tracking issue for the tool templates I would like robvis to support by default. Adding support for one of these tools should be a good first issue as it is a well contained problem and potential users can borrow from the existing infrastructure for other templates.

Tools to be covered:

• ROBIS
• PROBAST
• QUADAS-2 (applicability vs risk-of-bias - this one is a little different, I can provide more details if you are interested)
• QUIPS (added in Range of improvements #107)
• ROB-1 (now supported)

Some pointers:

• All added templates must be supported by both the rob_traffic_light() and rob_summary() functions
• All added templates must be comprehensively tested using vdiffr (see the testing framework for existing templates for reference)

If you are interested in tackling one of the not-yet-supported templates above, just comment below so I know which are being worked on to prevent duplication of effort!

[mcguinlu]

Theoretically, because of the way that the current "ROB1" tool option works, users can use any tool they like once they properly label their headings. However, adding specific templates allows for standards to be easily applied!

[mcguinlu]

QUIPS added in #107

[mcguinlu]

The applicability aspect of QUADAS-2 is now indirectly supported via domain shortcodes (see #138 for an example).

As the purpose of robvis is risk of bias visualisation, it is unlikely that I will create an additional template to directly support the applicability aspect of QUADAS-2.