feat: simple MText entity without columns

[DeepankarGupta13]

Added simple MText entity without columns.

[DeepankarGupta13]

@tarikjabiri sir, please check this PR.

[codecov[bot]]

Codecov Report

Patch coverage: 63.30% and project coverage change: -0.46 :warning:

Comparison is base (cb470d1) 94.66% compared to head (a30ee71) 94.21%.

:exclamation: Current head a30ee71 differs from pull request most recent head 43cd369. Consider uploading reports for the commit 43cd369 to get more accurate results

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #69 +/- ## ========================================== - Coverage 94.66% 94.21% -0.46% ========================================== Files 72 73 +1 Lines 7406 7515 +109 Branches 518 521 +3 ========================================== + Hits 7011 7080 +69 - Misses 395 435 +40 ``` | [Impacted Files](https://codecov.io/gh/dxfjs/writer/pull/69?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dxfjs) | Coverage Δ | | |---|---|---| | [src/Sections/EntitiesSection/EntitiesManager.ts](https://codecov.io/gh/dxfjs/writer/pull/69?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dxfjs#diff-c3JjL1NlY3Rpb25zL0VudGl0aWVzU2VjdGlvbi9FbnRpdGllc01hbmFnZXIudHM=) | `88.99% <30.00%> (-1.98%)` | :arrow_down: | | [src/DxfWriter.ts](https://codecov.io/gh/dxfjs/writer/pull/69?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dxfjs#diff-c3JjL0R4ZldyaXRlci50cw==) | `96.61% <58.82%> (-1.18%)` | :arrow_down: | | [src/Sections/EntitiesSection/Entities/MText.ts](https://codecov.io/gh/dxfjs/writer/pull/69?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dxfjs#diff-c3JjL1NlY3Rpb25zL0VudGl0aWVzU2VjdGlvbi9FbnRpdGllcy9NVGV4dC50cw==) | `68.29% <68.29%> (ø)` | | Help us with your feedback. Take ten seconds to tell us [how you rate us](https://about.codecov.io/nps?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dxfjs). Have a feature suggestion? [Share it here.](https://app.codecov.io/gh/feedback/?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=dxfjs)

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Do you have feedback about the report comment? Let us know in this issue.