Modified tags to support add values and removing default

[shawngib]

Description

Added the ability to use the tags parameter to add additional tags but not lose the default tags. Customers can still use something like tags='{"Owner":"Contoso","Cost Center":"2345-324"}' in bash to create a tag object then deploy with parameters like --parameters resourcePrefix="mlz-prod" deployASC="true" deployPolicy=true policy="CMMC" tags="$tags" which will not replace the current default use of prefix and deployment type tags.

Issue reference

The issue this PR will close: #530

Checklist

Please make sure you've completed the relevant tasks for this PR out of the following list:

• All acceptance criteria in the backlog item are met
• The documentation is updated to cover any new or changed features
• Manual tests have passed
• Relevant issues are linked to this PR

[glennmusa]

Changes make sense 👍. Have a nit regarding the variable name and wonder if the policy change should be in another merge.

Some more Boy Scouting, I noticed the hub resource group is missing a tags assignment. Can we update that in this change too?

missionlz/src/bicep/mlz.bicep

Lines 8 to 15 in 9a3529b

	module hubResourceGroup './modules/resourceGroup.bicep' = {
	name: 'deploy-rg-hub-${nowUtc}'
	scope: subscription(hubSubscriptionId)
	params: {
	name: hubResourceGroupName
	location: hubLocation
	}
	}