Enhance: Update dokan admin dashboard logo & add logo update notice.

[MdAsifHossainNadim]

Enhance: Update dokan admin logo & add logo update notice.

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• My code follow the WordPress' coding standards
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Changes proposed in this Pull Request:

Related Pull Request(s)

• Full PR Link

Closes

• Closes #3321

How to test the changes in this Pull Request:

• Go to dokan admin dashboard & see menu logo, admin settings logo, admin logo notice etc.

Changelog entry

Fix: Update dokan admin dashboard logo & add logo update notice.

Detailed Description of the pull request. What was previous behaviour
and what will be changed in this PR.

Before Changes

After Changes

Feature Video (optional)

Link of detailed video if this PR is for a feature.

PR Self Review Checklist:

• Code is not following code style guidelines
• Bad naming: make sure you would understand your code if you read it a few months from now.
• KISS: Keep it simple, Sweetie (not stupid!).
• DRY: Don't Repeat Yourself.
• Code that is not readable: too many nested 'if's are a bad sign.
• Performance issues
• Complicated constructions that need refactoring or comments: code should almost always be self-explanatory.
• Grammar errors.

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• Correct — Does the change do what it’s supposed to? ie: code 100% fulfilling the requirements?
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• Elegant — Does the change fit aesthetically within the overall style and architecture?

[MdAsifHossainNadim]

@shohag121 Vhaiya, kindly review this PR at your convenience.

[shashwatahalder01]

Scenario:
The icon needs to update on several places on dokan

[MdAsifHossainNadim]

@mrabbani Vhai, need to relevant ui's for new issues.
@shashwatahalder01 Vhai, If anything is required or if you have any suggestions for us, then feel free to inform us.

[shashwatahalder01]

@MdAsifHossainNadim, @mrabbani,
It would be better if we could introduce a new color pallet that is aligned with the latest dokan logo

[tuhin480]

Here is the Design Link. Please have a look.

[MdAsifHossainNadim]

@tuhin480 Vhai, we need to make consistent between existing banner & updated logo. Here is the preview after updating logo.

I think It will be better if we added some shadow or spaces on left/bottom side in this banner image. (as like as previous)

We need to update wp org's banner & icon logo's as per latest update.

CC: @mrabbani @ashrafux