feat: Allow resource names to be overridden when installing top-level module

[yotamat]

Fix violation of IAM naming constraints with postgresql in v1.3.1

Fixes the following error when using "postgresql" as db_engine:

Error: expected length of name to be in the range (1 - 64), got honeycomb-rds-cloudwatch-logs-honeycomb-rds-postgresql-log-parser

  with module.honeycomb-aws-integrations.module.rds_logs[0].module.rds_lambda_transform[0].aws_iam_role.lambda[0],
  on .terraform/modules/honeycomb-aws-integrations.rds_logs.rds_lambda_transform/iam.tf line 97, in resource "aws_iam_role" "lambda":
  97:   name                  = local.role_name

Reproduction

To reproduce the original error:

1. Deploy the main wrapper module using v1.3.1 as described in documentation here.
2. Set rds_db_engine = "postgresql".
3. Observe IAM naming constraints being exceeded on first deployment

Solution

Extracted hardcoded resource names to allow configurable variables with backward-compatible defaults.

Changes

Extracted hardcoded "honeycomb-..." resource names to variables with configurable defaults:

• cloudwatch_logs_name
• rds_logs_name
• cloudwatch_metrics_name
• s3_logfile_name

[MikeGoldsmith]

Looks great, thank you @yotamat 🎉