Primer Mixing LightRun OTProto template could be more generic

[Brad0440]

The Primer Mixing LightRun OTProto template (https://github.com/intbio-ncl/BiomationScripterLib/blob/main/BiomationScripter/OTProto/Templates.py) could be re-worked (and re-named?) to be more generic, rather than specific to lightrun sequencing reactions.

This could be achieved by:

• Adding in an optional argument for final volume
• Adding in an optional argument for final primer volume
• Adding in an optional argument for final DNA volume
• Adding in water as a reagent to make the final mix up to the final volume

[Brad0440]

This template has been re-named to Primer_Mixing and is now suitable for any generic protocol which requires the mixing of primer(s) with a DNA sample.

See: https://github.com/intbio-ncl/BiomationScripterLib/commit/0b0529eb122cfefb59dafa148daee510d22bf3f6