Raw content return for Grid DataColumn & Column

Need to have a method  `getDataCellContent` to return raw parsed data cell content. This is useful when extending these Columns, for processing any other data before formatting via `renderDataCellContent`.
Raw content return for Grid DataColumn & Column

Need to have a method  `getDataCellContent` to return raw parsed data cell content. This is useful when extending these Columns, for processing any other data before formatting via `renderDataCellContent`.
Raw content return for Grid DataColumn & Column
Raw content return for Grid DataColumn & Column
Removed unnecessary blank space
Removed unnecessary blank space
first draft of the extension generator
WIP merge ActiveRelation into ActiveQuery

allow extending only one class to add scopes, fixes #2146

TODO:

- [ ] adjust guide docs
- [ ] adjust README files of extensions
- [ ] finish work and fix test breaks
made createQuery() config param optional
added missing use statement
merged ActiveQueryInterface and ActiveRelatioInterface
Fixes #2426: Changed URL creation method signatures to be consistent
Allow using string for URL in case there are no parameters
moved `@include` tags of api docs directly into the class
Fixes #2425: Tabs widget now selects first tab if no active tab is specified
Validate login data only of there are no other errors
Added status condition to PasswordResetRequestForm email validator
Fixes #2508
allow configuring asset converter property with default class
updated docs about active relation