resource/aws_iot_topic_rule: Allow tags with '@' on creation

[gdavison]

Tags with @ are valid for IoT topic rules, but they were not accepted at creation time. The AWS API handles its own URL encoding for this call, while we were handling it.

Also validates S3 bucket object tags with @ which were using the same URL encoding call.

Closes #19653

Output from acceptance testing:

$ make testacc TESTARGS='-run=TestAccAWSIoTTopicRule_Tags\|TestAccAWSS3BucketObject_tags'

--- PASS: TestAccAWSIoTTopicRule_Tags (257.21s)
--- PASS: TestAccAWSS3BucketObject_tagsLeadingSingleSlash (320.11s)
--- PASS: TestAccAWSS3BucketObject_tagsMultipleSlashes (324.51s)
--- PASS: TestAccAWSS3BucketObject_tags (326.24s)
--- PASS: TestAccAWSS3BucketObject_tagsLeadingMultipleSlashes (326.33s)

$ make test TEST=./aws/internal/keyvaluetags

ok  	github.com/terraform-providers/terraform-provider-aws/aws/internal/keyvaluetags	0.617s

[ewbankkit]

Need to add .changelog/19677.txt.

[ewbankkit]

LGTM 🚀.

Commercial

% make testacc TEST=./aws TESTARGS='-run=TestAccAWSIoTTopicRule_Tags\|TestAccAWSS3BucketObject_tags'
==> Checking that code complies with gofmt requirements...
TF_ACC=1 go test ./aws -v -count 1 -parallel 20 -run=TestAccAWSIoTTopicRule_Tags\|TestAccAWSS3BucketObject_tags -timeout 180m
=== RUN   TestAccAWSIoTTopicRule_Tags
=== PAUSE TestAccAWSIoTTopicRule_Tags
=== RUN   TestAccAWSS3BucketObject_tags
=== PAUSE TestAccAWSS3BucketObject_tags
=== RUN   TestAccAWSS3BucketObject_tagsLeadingSingleSlash
=== PAUSE TestAccAWSS3BucketObject_tagsLeadingSingleSlash
=== RUN   TestAccAWSS3BucketObject_tagsLeadingMultipleSlashes
=== PAUSE TestAccAWSS3BucketObject_tagsLeadingMultipleSlashes
=== RUN   TestAccAWSS3BucketObject_tagsMultipleSlashes
=== PAUSE TestAccAWSS3BucketObject_tagsMultipleSlashes
=== CONT  TestAccAWSIoTTopicRule_Tags
=== CONT  TestAccAWSS3BucketObject_tagsLeadingMultipleSlashes
=== CONT  TestAccAWSS3BucketObject_tagsMultipleSlashes
=== CONT  TestAccAWSS3BucketObject_tags
=== CONT  TestAccAWSS3BucketObject_tagsLeadingSingleSlash
--- PASS: TestAccAWSIoTTopicRule_Tags (41.35s)
--- PASS: TestAccAWSS3BucketObject_tagsLeadingMultipleSlashes (100.50s)
--- PASS: TestAccAWSS3BucketObject_tagsMultipleSlashes (100.63s)
--- PASS: TestAccAWSS3BucketObject_tags (100.90s)
--- PASS: TestAccAWSS3BucketObject_tagsLeadingSingleSlash (100.93s)
PASS
ok  	github.com/terraform-providers/terraform-provider-aws/aws	104.718s

GovCloud

% make testacc TEST=./aws TESTARGS='-run=TestAccAWSIoTTopicRule_Tags\|TestAccAWSS3BucketObject_tags'
==> Checking that code complies with gofmt requirements...
TF_ACC=1 go test ./aws -v -count 1 -parallel 20 -run=TestAccAWSIoTTopicRule_Tags\|TestAccAWSS3BucketObject_tags -timeout 180m
=== RUN   TestAccAWSIoTTopicRule_Tags
=== PAUSE TestAccAWSIoTTopicRule_Tags
=== RUN   TestAccAWSS3BucketObject_tags
=== PAUSE TestAccAWSS3BucketObject_tags
=== RUN   TestAccAWSS3BucketObject_tagsLeadingSingleSlash
=== PAUSE TestAccAWSS3BucketObject_tagsLeadingSingleSlash
=== RUN   TestAccAWSS3BucketObject_tagsLeadingMultipleSlashes
=== PAUSE TestAccAWSS3BucketObject_tagsLeadingMultipleSlashes
=== RUN   TestAccAWSS3BucketObject_tagsMultipleSlashes
=== PAUSE TestAccAWSS3BucketObject_tagsMultipleSlashes
=== CONT  TestAccAWSIoTTopicRule_Tags
=== CONT  TestAccAWSS3BucketObject_tagsLeadingMultipleSlashes
=== CONT  TestAccAWSS3BucketObject_tagsMultipleSlashes
=== CONT  TestAccAWSS3BucketObject_tagsLeadingSingleSlash
=== CONT  TestAccAWSS3BucketObject_tags
--- PASS: TestAccAWSIoTTopicRule_Tags (60.03s)
--- PASS: TestAccAWSS3BucketObject_tagsLeadingMultipleSlashes (108.61s)
--- PASS: TestAccAWSS3BucketObject_tags (109.34s)
--- PASS: TestAccAWSS3BucketObject_tagsMultipleSlashes (109.79s)
--- PASS: TestAccAWSS3BucketObject_tagsLeadingSingleSlash (110.02s)
PASS
ok  	github.com/terraform-providers/terraform-provider-aws/aws	113.521s

[github-actions]

This functionality has been released in v3.45.0 of the Terraform AWS Provider. Please see the Terraform documentation on provider versioning or reach out if you need any assistance upgrading.

For further feature requests or bug reports with this functionality, please create a new GitHub issue following the template. Thank you!

[github-actions]

I'm going to lock this pull request because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active issues.
If you have found a problem that seems related to this change, please open a new issue and complete the issue template so we can capture all the details necessary to investigate further.