Fix 'pause' during cluster and advanced_cluster update

[maastha]

Description

Jira Ticket: https://jira.mongodb.org/browse/INTMDB-875

This Pr resolves bug from https://jira.mongodb.org/browse/HELP-46575 where we do not properly update 'pause' and 'unpause' attribute in mongodbatlas_cluster anf mongodbatlas_advanced_cluster resources.

Link to any related issue(s):

Type of change:

• Bug fix (non-breaking change which fixes an issue). Please, add the "bug" label to the PR.
• New feature (non-breaking change which adds functionality). Please, add the "enhancement" label to the PR.
• Breaking change (fix or feature that would cause existing functionality to not work as expected). Please, add the "breaking change" label to the PR.
• This change requires a documentation update
• Documentation fix/enhancement

Required Checklist:

• I have signed the MongoDB CLA
• I have read the contribution guidelines
• I have added tests that prove my fix is effective or that my feature works per HashiCorp requirements
• I have added any necessary documentation (if appropriate)
• I have run make fmt and formatted my code

Further comments

[andreaangiolillo]

LGTM if all tests are 🟢 . Great work here 💯

[Zuhairahmed]

LGTM!

[martinstibbe]

LGTM