If a tab is added to a new group and unnamed, a blank space is shown in vertical tab view

[MadhaviSeelam]

Description

Steps to Reproduce

1. Install 1.65.87
2. launch Brave
3. open few tabs
4. enable vertical tabs
5. add tab to a new group via context menu
6. do not name the group

Actual result:

A blank space is shown

Vertical tab view	Horizontal tab view

Expected result:

Selected color block should be shown.

Reproduces how often:

Easily

Brave version (brave://version info)

Brave | 1.65.87 Chromium: 123.0.6312.46 (Official Build) beta (64-bit)
-- | --
Revision | 2babfcf82ebba4c5dc0146d2ca66229ffd3ac02d
OS | Windows 11 Version 23H2 (Build 22631.3296)

Version/Channel Information:

• Can you reproduce this issue with the current release? Yes
• Can you reproduce this issue with the beta channel? Yes
• Can you reproduce this issue with the nightly channel? yes

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields?
• Does the issue resolve itself when disabling Brave Rewards?
• Is the issue reproducible on the latest version of Chrome?

Miscellaneous Information:

@rebron
cc: @brave/qa-team

[aguscruiz]

@zenparsing talking with @rebron we decided that we should give groups an incremental default name, starting with "Group 1".

If there are other groups already created, names would be "Group 2" "Group 3" and so on.

We'll also add a min-width to each group label, but I'll add more details to that in another issue.