chore: Updated changelog for v0.4.0

[PacoDw]

Description

• Updated changelog to v0.4.0
• changed dates as the Terraform changelog to have more coherency

Type of change:

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Required Checklist:

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

Further comments

[themantissa]

Edit to add the enhancements more clearly. Then ready Ty!

[themantissa]

LGTM - added internal reviewer as a heads that we are cutting 0.4.0 (and as a last check since there are more dependencies now). Once @gssbzn approves feel free to proceed.

Also side note, a few small things just got merged that are not in this list. I'm not concerned with adding them as the PRs can be reviewed and none should have a huge impact.

[gssbzn]

LGTM

[coderGo93]

LGTM