Support to config pdAddress by manual when user has no privs on INFORMATION_SCHEMA table.

[ZhendongBai]

What problem does this PR solve?

#2801

What is changed and how it works?

when fail to get pd address from INFORMATION_SCHEMA.CLUSTER_INFO, support config pdAddress by manual.

Check List

Tests

• No code

Code changes

• Has exported function/method change

Side effects

• Increased code complexity

Related changes

• Need to be included in the release note

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[shiyuhang0]

Please update the doc here to clarify the support of pd configuration.