utest: serials: move from examples to components/drivers/serial

[unicornx]

将 serial 驱动的 utest cases 从 examples 目录下移到 components/drivers/serial 下。

没有代码上的修改。只确保 Kconfig 可以正常工作。

为方便 review，本 PR 分为两个 commit：

• utest: serial: move from examples to components/drivers/serial
• utest: serial: update case names

[github-actions]

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为确保代码符合 RT-Thread 的编码规范，请在你的仓库中执行以下步骤运行代码格式化工作流（如果格式化CI运行失败）。
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[github-actions]

📌 Code Review Assignment

🏷️ Tag: components

Reviewers: Maihuanyi

Changed Files (Click to expand)

• components/drivers/serial/SConscript
• components/drivers/serial/utest/Kconfig
• components/drivers/serial/utest/SConscript
• components/drivers/serial/utest/bypass/SConscript
• components/drivers/serial/utest/bypass/bypass_conflict.c
• components/drivers/serial/utest/bypass/bypass_lower_run.c
• components/drivers/serial/utest/bypass/bypass_register.c
• components/drivers/serial/utest/bypass/bypass_upper_run.c
• components/drivers/serial/utest/v2/README.md
• components/drivers/serial/utest/v2/SConscript
• components/drivers/serial/utest/v2/posix/uart_posix_echo_block.c
• components/drivers/serial/utest/v2/posix/uart_posix_nonblock.c
• components/drivers/serial/utest/v2/qemu/uart_qemu_echo.c
• components/drivers/serial/utest/v2/uart_blocking_rx.c
• components/drivers/serial/utest/v2/uart_blocking_tx.c
• components/drivers/serial/utest/v2/uart_flush_rx.c
• components/drivers/serial/utest/v2/uart_flush_txb.c
• components/drivers/serial/utest/v2/uart_flush_txnb.c
• components/drivers/serial/utest/v2/uart_get_unread_bytes_count.c
• components/drivers/serial/utest/v2/uart_nonblocking_rx.c
• components/drivers/serial/utest/v2/uart_nonblocking_tx.c
• components/drivers/serial/utest/v2/uart_overflow_rxb_txb.c
• components/drivers/serial/utest/v2/uart_rxb_txb.c
• components/drivers/serial/utest/v2/uart_rxb_txnb.c
• components/drivers/serial/utest/v2/uart_rxnb_txb.c
• components/drivers/serial/utest/v2/uart_rxnb_txnb.c
• components/drivers/serial/utest/v2/uart_timeout_rxb.c
• components/drivers/serial/utest/v2/uart_timeout_rxb_txb.c
• components/drivers/serial/utest/v2/uart_timeout_txb.c

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📊 Current Review Status (Last Updated: 2025-10-11 14:24 CST)

• ⌛ Maihuanyi Pending Review

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[unicornx]

CI 的失败看上去和本次 pr 修改无关，请检查 @Rbb666