feat: add capitalize and titleCase method for i18n

[warjiang]

What type of PR is this?
/kind feature

What this PR does / why we need it:

1. capitalize or titleCase for some special usages.

• sidebar case:
  
• table column case:
  
• card case:
  
• segment case:
  

2. set english as default language.

Which issue(s) this PR fixes:
Fixes #

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

1. capitalize or titleCase for some special cases
2. set english as default language for dashboard

[RainbowMango]

Shall we always use title case?

[warjiang]

+1, for this case capitalize and titleCase method share the same effect, but titleCase is more suitable.

[warjiang]

/assign @RainbowMango @samzong

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[samzong]

It seems unnecessary to handle it like this. recommended to correct the i18n text, otherwise, this part of the code logic will confuse users; Additionally, will there be any issues when concatenating prompt words?

[warjiang]

yes~. Only for some corner-case, there is need to use capitalize、titleCase、lowerCase kinds of method. For example, assume that we need to translate 概览 into overview, for some cases, like the sidebard menu or card title, we need to use Overview, for some other cases, like tag view, we need to use overview in lowercase, but these kind of cases if not very common. So just change the translation dictionary firstly, for corner case, use format method. cc @RainbowMango

[RainbowMango]

I feel it is kind of redundant to add titleCase to each term. I prefer to correct it at i18n text.

for some cases, like the sidebard menu or card title, we need to use Overview, for some other cases, like tag view, we need to use overview in lowercase, but these kind of cases if not very common.

Then define two terms to differentiate them.