Add Dublin trees data

[LiamOSullivan]

Would be suitable as webGL version of OD's tool or as e.g. three.js visualisation

Need to manage the data pipeline as it is >700MB zipped

https://zenodo.org/record/3813792#.Xx_22vhKiLJ

[LiamOSullivan]

Interesting aspects of the data:

• Gives a timeline of when trees were added which could be used a narrative
• Can filter by species, height and some other properties
• Ego-centric discovery of local trees

Cons

• Not being updated regularly and/or frequently (?)
• Crowd-sourced