TERRA-114 ⁃ Support table definitions from `CREATE` statements

[SpencerC]

The current approach requires describing table schemas through a bespoke representation. I'd wager most clients with explicit schemas have them defined in CREATE statement form.

Current Approach

resource "astra_database" "dev" {
  name           = "puppies"
  keyspace       = "puppies"
  cloud_provider = "gcp"
  regions        = ["us-east1"]
}
resource "astra_table" "table-1" {
  table       = "mytable"
  keyspace = "puppies"
  database_id = astra_database.dev.id
  region = "us-east1"
  clustering_columns = "a:b"
  partition_keys = "c:d"
  column_definitions= [
    {
      Name: "a"
      Static: false
      TypeDefinition: "text"
    },
    {
      Name: "b"
      Static: false
      TypeDefinition: "text"
    },
    ...
  ]
} 

Proposed Approach

environments/prod/main.tf:

resource "astra_database" "dev" {
  name           = "puppies"
  keyspace       = "puppies"
  cloud_provider = "gcp"
  regions        = ["us-east1"]
}
resource "astra_table" "table-1" {
  keyspace = "puppies"
  database_id = astra_database.dev.id
  region = "us-east1"
  schema_path = "../../db/mytable.cql"
} 

db/mytable.cql:

CREATE TABLE mytable
(
    a   TEXT,
    b  TEXT,
    ...
    PRIMARY KEY ((c,d), a, b)
);

┆Issue is synchronized with this Jira Task by Unito
┆Issue Number: TERRA-114
┆Priority: Major