Add aws_ec2_placement_group table

[cbruno10]

Example query results

Results

### List all placement groups and their strategies

```sql
select
  group_name,
  strategy,
  state,
  region
from
  aws_ec2_placement_group;

group_name	strategy	state	region
test-steampipe-pg	partition	available	us-east-1

---

List all available partition placement groups

select
  group_name,
  partition_count,
  state
from
  aws_ec2_placement_group
where
  strategy = 'partition'
  and state = 'available';

group_name	partition_count	state
test-steampipe-pg	3	available

---

Count of placement groups by strategy

select
  strategy,
  count(*) as count
from
  aws_ec2_placement_group
group by
  strategy;

strategy	count
partition	1

---

List placement groups with fewer than 3 partitions

select
  group_name,
  partition_count,
  strategy
from
  aws_ec2_placement_group
where
  partition_count < 3;

No rows returned (all partition_count values are 3 or greater).

---

List all partition placement groups and their partition counts

select
  group_name,
  partition_count,
  state
from
  aws_ec2_placement_group
where
  strategy = 'partition';

group_name	partition_count	state
test-steampipe-pg	3	available

</details>

[Copilot]

Pull Request Overview

This PR introduces the aws_ec2_placement_group table to allow users to query AWS EC2 Placement Groups using SQL. Key changes include:

• Adding documentation with examples in docs/tables/aws_ec2_placement_group.md.
• Implementing the table definition and query functions in aws/table_aws_ec2_placement_group.go.
• Registering the new table in aws/plugin.go.

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
docs/tables/aws_ec2_placement_group.md	New documentation file with usage details and SQL examples.
aws/table_aws_ec2_placement_group.go	New table implementation with list and get functions.
aws/plugin.go	Updated table registrations to include the new placement group.