Improve member check and IAM

[devksingh4]

• Remove dependence on Entra ID for membership checks
• Get user and group roles from the same table

[github-actions]

💰 Infracost report

Monthly estimate increased by $6 📈

Changed project	Baseline cost	Usage cost*	Total change	New monthly cost
acm-uiuc/core/terraform/envs/prod	+$0	+$3	+$3 (+5%)	$62
acm-uiuc/core/terraform/envs/qa	+$0	+$3	+$3 (+2%)	$152

*Usage costs were estimated using infracost-usage.yml, see docs for other options.

Estimate details (includes details of unsupported resources)

Key: * usage cost, ~ changed, + added, - removed

──────────────────────────────────
Project: envs-prod
Module path: envs/prod

+ module.dynamo.aws_dynamodb_table.iam_assignments
  +$3

    + Write request unit (WRU)
      +$0.00, +150 WRUs*

    + Read request unit (RRU)
      +$0.00, +300 RRUs*

    + Data storage
      +$0.75, +3 GB*

    + Point-In-Time Recovery (PITR) backup storage
      +$1, +6 GB*

    + On-demand backup storage
      +$0.60, +6 GB*

    + Table data restored
      +$0.45, +3 GB*

    + Streams read request unit (sRRU)
      +$0.00, +700 sRRUs*

Monthly cost change for acm-uiuc/core/terraform/envs/prod (Module path: envs/prod)
Amount:  +$3 ($59 → $62)
Percent: +5%

──────────────────────────────────
Project: envs-qa
Module path: envs/qa

+ module.dynamo.aws_dynamodb_table.iam_assignments
  +$3

    + Write request unit (WRU)
      +$0.00, +150 WRUs*

    + Read request unit (RRU)
      +$0.00, +300 RRUs*

    + Data storage
      +$0.75, +3 GB*

    + Point-In-Time Recovery (PITR) backup storage
      +$1, +6 GB*

    + On-demand backup storage
      +$0.60, +6 GB*

    + Table data restored
      +$0.45, +3 GB*

    + Streams read request unit (sRRU)
      +$0.00, +700 sRRUs*

Monthly cost change for acm-uiuc/core/terraform/envs/qa (Module path: envs/qa)
Amount:  +$3 ($149 → $152)
Percent: +2%

──────────────────────────────────
Key: * usage cost, ~ changed, + added, - removed

*Usage costs were estimated using infracost-usage.yml, see docs for other options.

204 cloud resources were detected:
∙ 96 were estimated
∙ 106 were free
∙ 2 are not supported yet, see https://infracost.io/requested-resources:
  ∙ 2 x aws_cloudfront_key_value_store

Infracost estimate: Monthly estimate increased by $6 ↑
┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━┳━━━━━━━━━━━━━━┓
┃ Changed project                                    ┃ Baseline cost ┃ Usage cost* ┃ Total change ┃
┣━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━╋━━━━━━━━━━━━━━━╋━━━━━━━━━━━━━╋━━━━━━━━━━━━━━┫
┃ acm-uiuc/core/terraform/envs/prod                  ┃           +$0 ┃         +$3 ┃    +$3 (+5%) ┃
┃ acm-uiuc/core/terraform/envs/qa                    ┃           +$0 ┃         +$3 ┃    +$3 (+2%) ┃
┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┻━━━━━━━━━━━━━━━┻━━━━━━━━━━━━━┻━━━━━━━━━━━━━━┛

_{This comment will be updated when code changes.}