* docs: Add comments to standalone config example
* docs: Add comments to datanode config example
* docs: Add comments to frontend config example
* docs: Add comments to meta-srv config example
* docs: Use "GB" instead of "GiB"
* docs: Add link to the selector doc
* docs: Fix grammar
* fix: Serialize FrontendOptions to toml
* fix: Serialize DatanodeOptions to toml
* fix: Serialize StandaloneOptions to toml
See https://users.rust-lang.org/t/why-toml-to-string-get-error-valueaftertable/85903/2
* chore!: Rename MetaClientOpts to MetaClientOptions
BREAKING CHANGE: Change the meta_client_opts in the config file to
meta_client_options
* refactor: options and sample configurations
* chore: newline at end of file
* chore: format code
* chore: remove comment and set sample configurations to default values
* chore: use single quoted string in sample configuration files
* feat: frontend instance
* no need to carry column length in `Column` proto
* add more tests
* rebase develop
* create a new variant with already provisioned RecordBatches in Output
* resolve code review comments
* new frontend instance does not connect datanode grpc
* add more tests
* add more tests
* rebase develop
Co-authored-by: luofucong <luofucong@greptime.com>