Add support for various geometric column types, similiar to PostgreSQL.

The types would be the following:

• point (Point on a plane) -> (x,y)
• line (Infinite line) -> {A,B,C}
• lseg (Finite line segment) -> ((x1,y1),(x2,y2))
• box (Rectangular box) -> ((x1,y1),(x2,y2))
• path (Closed path) -> ((x1,y1),...)
• path (Open path) -> [(x1,y1),...]
• polygon (Multiple points) -> ((x1,y1),...)
• circle (center point and radius) -> <(x,y),r>

PostgreSQL geometric type documentation: https://www.postgresql.org/docs/10/static/datatype-geometric.html

Issue is a nice to have for my use cases

Jira issue: CRDB-5891