feat(electric): Add support for the float4 column type

[alco]

No description provided.

[linear]

VAX-846 Implement support for float4 type

Reference: https://electric-sql.slab.com/posts/data-validation-supporting-more-postgres-types-tpegouhj#h1sz5-supporting-more-basic-postgres-types-in-electric.

• Implement server-side validation that ensures a given string-formatted number can fit into float4. In Elixir, This can presumably be achieved with <<f::float-32>> = <<num::float-32>> where num is a floating-point number to be validated. If I understand correctly, the pattern matching will fail if num does not fit into a 32-bit float. Even if that's not the case, the comparison f === num should finish the job for sure.
• Look into how the [extra_float_digits](https://www.postgresql.org/docs/11/datatype-numeric.html#DATATYPE-FLOAT) setting affects the values in the logical replication stream.
• Add float4 to the list of supported data types
• Mention float4 in the data type docs
• Add an E2E test that verifies syncing of float4 values

[magnetised]

that's a fun one. great stuff. are we numerically complete now?

[alco]

that's a fun one. great stuff. are we numerically complete now?

Good one. We still have Postgres' decimal / numeric data type to work on.

[icehaunter]

Great job!