Remove root admin validations

[inthirakumaaran]

Related to wso2/product-is#22411

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Changes

Add tenant form

• Remove root admin username and password validation
• Validate admin email

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Edit tenant form

• Remove root admin username validation(Password validation will be preserved in align with API)
• Validate admin email

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 41.85%. Comparing base (3e098ee) to head (10dc208).
Report is 111 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #7648   +/-   ##
=======================================
  Coverage   41.85%   41.85%           
=======================================
  Files          42       42           
  Lines         939      939           
  Branches      238      217   -21     
=======================================
  Hits          393      393           
- Misses        502      546   +44     
+ Partials       44        0   -44     

Flag	Coverage Δ
@wso2is/core	41.85% <ø> (ø)

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see 12 files with indirect coverage changes

[pavinduLakshan]

Let's fix the lint issues.